                      807

                                    SEPARATE OPINION OF JUDGE ROBINSON

                         Failure of the Court to rule on the merits of the claim that Nicaragua breached
                      the prohibition of the use of force set out in Article 2 (4) of the
                      United Nations Charter — the centrality of that prohibition in the United Nations
                      Charter system for the maintenance of international peace and security — the need
                      for the Court to adopt a practice of ruling on the merits of a claim for a breach of
                      Article 2 (4) of the United Nations Charter, unless the claim is patently
                      unmeritorious or frivolous — the assumption that reparation for a breach of
                      territorial sovereignty sufficiently addresses a breach of the prohibition of the use
                      of force — international law envisages a spectrum of activities that may breach
                      Article 2 (4) of the United Nations Charter — the finding that in this case a
                      breach of Article 2 (4) of the United Nations Charter has been committed.

                         1. As my votes indicate, I am in broad agreement with the Court’s
                      decision in this case. I write separately to explain my vote against the
                      Court’s rejection in paragraph 229 (7) of all other submissions made by
                      the Parties.
                         2. In its final submissions, 2 (b) (ii), Costa Rica asked the Court to
                      find a breach by Nicaragua of “the prohibition of the threat or use of
                      force under Article 2 (4) of the United Nations Charter and Article 22 of
                      the Charter of the Organization of American States” 1. In its earlier sub-
                      missions, Costa Rica also asked the Court to find Nicaragua responsible
                      for its violation of the prohibition of the threat or use of force pursuant
                      to Article 2 (4) of the United Nations Charter, and Articles 1, 19, 21, 22
                      and 29 of the Charter of the Organization of American States 2.

                        3. I am of the opinion that the facts establish Nicaragua’s breach of
                      Article 2 (4) of the United Nations Charter and that in the circumstances
                      of this case the Court should have separately and explicitly determined
                      the claim that there was a breach of that provision. The opinion also
                      argues that the Court should adopt a practice of determining the merits
                      of a claim that Article 2 (4) of the United Nations Charter has been
                      breached, unless the claim is patently unmeritorious or frivolous. In this

                         1 CR 2015/14, p. 68, para. 2 (b) (ii) ; see paragraph 97 of the Judgment.
                         2 Memorial of Costa Rica (MCR), Submissions, p. 303, para. 1 (b) (invoking
                      Article 2 (4) of the UN Charter and Article 1, 19, 21 and 29 of the OAS Charter) ;
                      CR 2015/14, p. 68, para. 2 (b) (ii) (invoking Article 2 (4) of the UN Charter and Article 22
                      of the OAS Charter).

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                      opinion, I also explain my hesitations regarding what appears to be the
                      Court’s finding that, in this case, reparation awarded for a breach of ter-
                      ritorial sovereignty would sufficiently address the injury suffered as a
                      result of any potential breach of Article 2 (4).

                        4. This opinion is divided as follows :
                      A. The Court’s approach
                      B. The background
                      C. The need for the Court to determine the merits of a claim that there is
                         a breach of Article 2 (4) of the United Nations Charter

                      D. Interpreting paragraph 97
                      E. The determination of a breach of Article 2 (4) of the United Nations
                         Charter
                          (i) The gravity of Nicaragua’s actions
                         (ii) Purpose
                      F. Conclusion

                                              A. The Court’s Approach

                        5. In ruling on Costa Rica’s submissions about the prohibition of the
                      threat or use of force, the Court states the following in paragraph 97 :

                               “The fact that Nicaragua considered that its activities were taking
                            place on its own territory does not exclude the possibility of charac-
                            terizing them as unlawful use of force. This raises the issue of their
                            compatibility with both the United Nations Charter and the Charter
                            of the Organization of American States. However, in the circum-
                            stances, given that the unlawful character of these activities has
                            already been established, the Court need not dwell any further on this
                            submission. As in the case concerning Land and the Maritime Bound‑
                            ary between Cameroon and Nigeria (Cameroon v. Nigeria : Equatorial
                            Guinea intervening), the Court finds that, ‘by the very fact of the
                            present Judgment and the evacuation’ of the disputed territory, the
                            injury suffered by Costa Rica ‘will in all events have been sufficiently
                            addressed’ (Judgment, I.C.J. Reports 2002, p. 452, para. 319).”

                         6. In doing so, the Court follows its approach in Land and Maritime
                      Boundary (Cameroon v. Nigeria). In that case, Cameroon had asked the
                      Court to adjudge and declare that by “invading and occupying its terri-
                      tory”, Nigeria had violated its conventional and customary obligations ;
                      in particular, the prohibition of the use of force, the principle of non‑inter-

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                      vention and Cameroon’s territorial sovereignty 3. Cameroon argued that
                      Nigeria was under an obligation to end its presence in Cameroonian ter-
                      ritory, evacuate any occupied areas, refrain from such acts in future, and
                      to make reparation for material and non‑material injury 4. Given the
                      unsettled nature of the boundary, Nigeria argued that it believed its
                      actions were lawful 5.

                         7. The evidence shows that the acts pleaded by Cameroon included at
                      least 80 incidents 6, some of them resulting in loss of life 7 due to active
                      engagements between Cameroonian and Nigerian military forces on
                      Cameroonian territory and arrests by military forces. The alleged acts
                      had taken place over a 15‑year period and the large majority occurred on
                      parts of the territory that were in dispute 8.
                         8. The Court found that, in light of its decision on the boundary
                      between the two States, Nigeria was under an obligation to withdraw its
                      civilian and military presence from occupied areas that the Court had
                      found to belong to Cameroon 9. The Court did not explicitly adjudicate
                      Cameroon’s claims of breach of the prohibition of the use of force 10,
                      holding that :
                              “In the circumstances of the case, the Court considers moreover
                            that, by the very fact of the present Judgment and of the evacuation
                            of the Cameroonian territory occupied by Nigeria, the injury suffered

                         3 Land and Maritime Boundary between Cameroon and Nigeria (Cameroon v. Nigeria :

                      Equatorial Guinea intervening), Judgment, I.C.J. Reports 2002, p. 450, para. 310.
                         4 Ibid.
                         5 Ibid., p. 451, para. 311.
                         6 Land and Maritime Boundary between Cameroon and Nigeria (Cameroon v. Nigeria),

                      Memorial of Cameroon, pp. 564‑595 ; Observations by the Republic of Cameroon on the
                      Preliminary Objections of Nigeria, Book II (C.O. Ann. 1) ; Counter‑Memorial of Nigeria,
                      pp. 653‑800.
                         7 While there appears to have been disagreement between the Parties about the number

                      of persons killed, it is clear that lives were lost. For example, Cameroon and Nigeria
                      appear to agree on the fact that during the military exchange between the two countries
                      on 16 May 1981, some Nigerian soldiers died, Reply of Cameroon, p. 505, para. 11.58 ;
                      Memorial of Cameroon, pp. 567‑569, paras. 6.12‑6.27 ; in relation to an exchange of fire
                      between the two countries on 3 February 1996, Nigeria states in its Rejoinder “thus what
                      Cameroon presents as a carefully prepared surprise attack by Nigeria killed or wounded
                      30 Nigerian civilians”, Rejoinder of Nigeria, Part V, State Responsibility and Counter-
                      Claims, Chap. 16, Appendix, para. 160.
                         8 Land and Maritime Boundary between Cameroon and Nigeria (Cameroon v. Nigeria),

                      Memorial of Cameroon, pp. 564‑595 ; Observations by the Republic of Cameroon on the
                      Preliminary Objections of Nigeria, Book II (C.O. Ann. 1) ; Counter-Memorial of Nigeria,
                      pp. 653‑800.
                         9 Land and Maritime Boundary between Cameroon and Nigeria (Cameroon v. Nigeria :

                      Equatorial Guinea intervening), Judgment, I.C.J. Reports 2002, p. 451, para. 314.
                         10 Christine Gray, “The International Court of Justice and the Use of Force” in Chris-

                      tian J. Tams and James Sloan (eds.), The Development of International Law by the Interna‑
                      tional Court of Justice, Oxford University Press, 2013, p. 237 (fn. 7).

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                            by Cameroon by reason of the occupation of its territory will in all
                            events have been sufficiently addressed. The Court will not therefore
                            seek to ascertain whether and to what extent Nigeria’s responsibility
                            to Cameroon has been engaged as a result of that occupation.” 11
                         9. The Court went on to decide that, in respect of “various boundary
                      incidences” alleged by both Parties to breach the other Party’s interna-
                      tional obligations, neither Party had proved their case 12.

                                                   B. The Background

                         10. The Judgment does not set out in detail the facts which substanti-
                      ate Costa Rica’s claim of a breach of Article 2 (4) of the
                      United Nations Charter. The treatment of this issue is very sparse, being
                      confined to: (i) paragraphs 66 and 67, which mention Nicaragua’s place-
                      ment of military units in the area of Isla Portillos with the indication that
                      the matter would be considered in relation to Nicaragua’s compliance
                      with the Court’s Order on provisional measures, of 8 March 2011;
                      (ii) paragraph 93, where the Court finds that Nicaragua’s activities were a
                      breach of Costa Rica’s territorial sovereignty; (iii) paragraph 97, in which
                      the Court finds that the injury suffered by Costa Rica will in all events
                      have been sufficiently addressed; (iv) paragraphs 121 to 129, which
                      address the question of Nicaragua’s compliance with provisional mea-
                      sures ; and (v) paragraph 139 and 142, in which the Court deals with rep-
                      aration for certain activities by Nicaragua, are also relevant to the
                      discussion.

                         11. These paragraphs have to be read along with relevant passages
                      from the pleadings of the Parties. The Court has held, in paragraph 67 of
                      the Judgment, that violations that occurred in 2013, although taking
                      place after Costa Rica’s Application was filed, may be examined “as part
                      of the merits of the claim” since “they concern facts which are of the same
                      nature as those covered in the Application and which the Parties had the
                      opportunity to discuss in their pleadings”. As such, they are considered in
                      this opinion.

                        12. Nicaragua and Costa Rica have a history of an at times difficult
                      and fractious relationship. In 1857, one year before the adoption of the
                      Treaty of Limits, there were hostilities between the two countries. During
                      the well‑known period of conflict between the Sandinista government in

                        11 Land and Maritime Boundary between Cameroon and Nigeria (Cameroon v. Nigeria :

                      Equatorial Guinea intervening), Judgment, I.C.J. Reports 2002, p. 452, para. 319.
                        12 Ibid., p. 453, paras. 323‑324.

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                      Nicaragua and the Contras in the 1980s, some of the Contras operated
                      from camps established in Costa Rica.
                         13. On 31 October 2010, Costa Rica became aware that the Costa Rican
                      flag at Finca Aragón had been removed, and noticed Nicaraguan military
                      camps in that area. On 1 November 2010, Costa Rica noticed the pres-
                      ence of Nicaraguan personnel close to the first caño during an overflight
                      of the area of Finca Aragón in Costa Rica 13. During this overflight Nica-
                      raguan personnel pointed AK-47s, and one soldier appears to be pointing
                      an anti-aircraft type missile, at the Costa Rican aircraft 14. On the same
                      day, the Costa Rican Foreign Minister sent a note to the Minister for
                      Foreign Affairs of Nicaragua protesting the presence of the military per-
                      sonnel 15.
                         14. Costa Rica further raised the situation with the Organization of
                      American States (OAS) on 3 November, but efforts to find a consensual
                      solution failed. On 12 November 2010, the Permanent Council of the
                      OAS, by a majority of 22 votes in favour, with two votes against (Nicara-
                      gua and Venezuela) and three abstentions, adopted the OAS Secretary‑
                      General’s recommendation to demilitarize the area of Isla Portillos 16.

                        15. In a speech on the following day, Nicaraguan President Daniel
                      Ortega denied the propriety of the OAS vote, asserting that Costa Rica
                      was occupying and attempting to take possession of Nicaraguan territory
                      to the north-east of the first caño 17.
                        16. On 18 November 2010, Costa Rica decided to file the Application
                      for the Certain Activities proceedings and at the same time requested the
                      Court to indicate provisional measures of protection 18.

                         13  CR 2011/1, p. 30, para. 24.
                         14  Ibid.
                         15  Ibid., pp. 30‑31, para. 25.
                         16 CP/RES. 978 (1777/10), “Situation in the Border Area Between Costa Rica and

                      Nicaragua” (12 Nov. 2010), available at http://www.oas.org/council/resolutions/res978.
                      asp ; see also Certain Activities Carried Out by Nicaragua in the Border Area (Costa Rica v.
                      Nicaragua), Provisional Measures, Order of 8 March 2011, I.C.J. Reports 2011 (I), p. 10,
                      para. 16.
                         17 Application of Costa Rica, Attachment 6, p. 70, Speech by President‑Commander

                      Daniel Ortega, Defending the Sovereign Right of the Nicaraguan People over the San Juan
                      River (English translation), 13 Nov. 2010, 19:25: “We as the harmed party [of the case],
                      because we are being harmed by Costa Rica, will have recourse to the Court and denounce
                      Costa Rica for wanting to occupy Nicaraguan territory, because this is what Costa Rica
                      wants ! To take possession of Nicaraguan territory”, ibid., p. 88; “Then there is the area
                      they called Isla Portillos, as well ; and then there is this area where we have the lagoon and
                      the channel where we are working on, and here, we are already in Nicaraguan territory. In
                      Costa Rican territory, we have neither occupied Isla Calero, that is not true ! Nor occupied
                      what they call Isla Portillos . . . there are no soldiers or police there.” Ibid., p. 76.
                         18 Certain Activities Carried Out by Nicaragua in the Border Area (Costa Rica v.

                      Nicaragua), Provisional Measures, Order of 8 March 2011, I.C.J. Reports 2011 (I), p. 9,
                      para. 11.

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                         17. On 7 December 2010, Special Adviser to the OAS Secretary‑
                      General, Ambassador Caputo, after conducting an overflight, reported to
                      the OAS that he “saw no members of the armed forces on the ground”,
                      but went on to say that this “does not necessarily mean that there were
                      none. In contrast, the military presence on board the dredger was
                      obvious.” 19
                         18. During the Court’s January 2011 hearings for Costa Rica’s request
                      for the indication of provisional measures, Costa Rica presented evidence
                      that the Nicaraguan military presence in the disputed territory had
                      increased 20. In this context, counsel for Costa Rica also made reference to
                      alleged Nicaraguan violations of Costa Rica’s territorial waters in the
                      Caribbean Sea and “underline[d] that the inhabitants of the region are
                      extremely worried and scared” 21.

                         19. During its oral pleadings before the Court on 11 January 2011,
                      Nicaragua stated that “there are no troops in the swampland. There is no
                      permanent military post in the area.” 22
                         20. On 19 January 2011, a Costa Rican overflight established that
                      Nicaraguan military personnel continued to be present on the disputed
                      territory and that the size of their encampment had increased since Octo-
                      ber 2010 23.
                         21. The Court, in its Order for provisional measures of 8 March 2011,
                      required both Parties to “refrain from sending to, or maintaining in the
                      disputed territory, including the caño, any personnel, whether civilian,
                      police or security” 24.
                         22. However, about two years later, in a photograph dated 5 Febru-
                      ary 2013 and submitted to the Court on 15 March 2013, a new military
                      camp was visible on the beach 25. On 18 September 2013, a Costa Rican
                      overflight provided further evidence of the Nicaraguan military troops
                      and camps on the beach within the disputed territory 26.

                        23. During Nicaragua’s oral pleadings on 15 and 17 October 2013 in
                      response to Costa Rica’s request for new provisional measures, Nicara-

                         19 Report of the OAS Secretary-General, pursuant to resolution CP/RES. 979 (1780/10),

                      presented to the Twenty‑Sixth Meeting of Consultation of Ministers of Foreign Affairs,
                      7 December 2010, cited in CR 2011/1, pp. 33‑34, para. 36.
                         20 Ibid., p. 35, para. 46.
                         21 Ibid., para. 47.
                         22 CR 2011/2, p. 13, para. 28.
                         23 MCR, p. 93, para. 3.53, citing Vol. 5, Ann. 223.
                         24 Certain Activities Carried Out by Nicaragua in the Border Area (Costa Rica v. Nica‑

                      ragua), Provisional Measures, Order of 8 March 2011, I.C.J. Reports 2011 (I), p. 27,
                      para. 86 (1).
                         25 Certain Activities Carried Out by Nicaragua in the Border Area (Costa Rica v. Nica‑

                      ragua) — Construction of a Road in Costa Rica along the San Juan River (Nicaragua v.
                      Costa Rica), Provisional Measures, Order of 22 November 2013, I.C.J. Reports 2013,
                      p. 365, para. 46.
                         26 CR 2013/24, p. 21, para. 18.

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                      gua claimed that Costa Rica had been aware of the “Nicaraguan military
                      detachment” for almost two years and that its purpose was to fight drug
                      trafficking 27. Nicaragua also pointed out that in its request for new pro-
                      visional measures, Costa Rica did not, again, complain about Nicaraguan
                      military presence 28.

                         24. In its Order of provisional measures of 22 November 2013, the
                      Court found that the photograph dated 5 February 2013 did show a
                      “Nicaraguan army encampment” and that “military personnel” had been
                      stationed there since at least 5 February 2013 29. The Court also held that
                      the encampment was within the disputed territory 30. In the Order’s oper-
                      ative paragraph the Court again explicitly required Nicaragua to remove,
                      and consequently prevent from entering, any “civilian, police or security”
                      personnel 31.

                         25. In conclusion, the evidence before the Court establishes the pres-
                      ence of Nicaraguan military personnel from at least 1 November 2010 to
                      19 January 2011 on what the Court today has confirmed is Costa Rican
                      territory. The Nicaraguan military was therefore on Costa Rican territory
                      for just over 11 weeks in the years 2010‑2011.

                        26. The evidence before the Court further establishes that from 5 Feb-
                      ruary 2013 until sometime shortly before 22 November 2013, a period of
                      nine months, Nicaragua had an established military presence on the beach,
                      which is also, as confirmed by the Judgment, Costa Rican territory.

                               C. The Need for the Court to Determine the Merits
                                of a Claim that there Is a Breach of Article 2 (4)
                                         of the United Nations Charter

                        27. The prohibition of the threat or use of force is a foundational rule
                      of the international legal system. It has been described by the Court as “a
                      cornerstone of the United Nations Charter” 32. The prohibition has been
                      deemed to “represent . . . beside the protection of human rights, ‘the
                      major achievement of the international legal order in the 20th century . . .

                         27 CR 2013/27, p. 16, para. 35.
                         28 Ibid., p. 17, para. 36.
                         29 Certain Activities Carried Out by Nicaragua in the Border Area (Costa Rica v. Nica‑
                      ragua) — Construction of a Road in Costa Rica along the San Juan River (Nicaragua v.
                      Costa Rica), Provisional Measures, Order of 22 November 2013, I.C.J. Reports 2013,
                      p. 365, para. 46.
                         30 Ibid.
                         31 Ibid., p. 369, para. 59 (2) (C).
                         32 Armed Activities on the Territory of the Congo (Democratic Republic of the Congo v.

                      Uganda), Judgment, I.C.J. Reports 2005, p. 223, para. 148.

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                      the cornerstone of that order and an undisputed core principle of the
                      international community’” 33.

                         28. Up to the end of World War I, and despite early twentieth-century
                      attempts to the contrary, international law did not prohibit the use of
                      force among States. Significantly, the Covenant of the League of Nations
                      did not contain a general prohibition on the use of force. Article 11
                      defined war and the threat of war as a “matter of concern to the whole
                      League”, but only in specific circumstances were States prohibited from
                      resorting to war 34. It was only after Article 1 of the Kellogg‑Briand Pact
                      was adopted in 1928 that “recourse to war” was prohibited. It was
                      renounced “as an instrument of national policy” by the majority of
                      States 35. It took the atrocities of World War II to convince States to
                      agree on the prohibition of force in its modern form. It is found in Arti-
                      cle 2, paragraph 4, of the Charter of the United Nations and reads as
                      follows :

                                “The Organization and its Members, in pursuit of the Purposes
                            stated in Article 1, shall act in accordance with the following Princi-
                            ples
                            �����������������������������������������������������������������������������������������������������������������
                                4. All Members shall refrain in their international relations from
                            the threat or use of force against the territorial integrity or political
                            independence of any state, or in any other manner inconsistent with
                            the Purposes of the United Nations.”

                        29. The history of the prohibition of the use of force, and in particular,
                      the difficulties encountered by the international community in arriving at
                      agreement on the prohibition, is one indication of its pivotal role in the
                      architecture established after World War II for the maintenance of inter-
                      national peace and security. The centrality of that role is no doubt one of
                      the factors explaining why the prohibition has the status not only of a
                      rule of customary international law, but also of a peremptory norm of

                         33 Oliver Dörr, Albrecht Randelzhofer, “Chapter I Purposes and Principles,

                      Article 2 (4)”, in Bruno Simma, Daniel‑Erasmus Khan, Georg Nolte, Andreas Paulus,
                      (eds.), Nikolai Wessendorf (assistant ed.), The Charter of the United Nations : A Commen‑
                      tary, Vol. I, 3rd ed., Oxford University Press, 2012, para. 71.
                         34 Covenant of the League of Nations, Arts. 11‑13.
                         35 The initial parties were Australia, Belgium, Canada, Czechoslovakia, France,

                      Germany, British India, the Irish Free State, Italy, Japan, New Zealand, Poland,
                      South Africa, the United Kingdom and the United States of America. Forty more States
                      also adopted the Pact. A similar provision in the Saavedra Lamas Treaty applies to many
                      of the Latin American States.

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                      general international law from which no derogation is permitted 36. The
                      virtual universal acceptance of this norm through membership of the
                      United Nations also serves to highlight the significance of the prohibition.
                         30. The United Nations Charter also highlights the important role the
                      Court has in the peaceful settlement of disputes, “the continuance of which
                      is likely to endanger the maintenance of international peace and security”
                      and thus undermine the purposes of the United Nations Charter 37. Arti-
                      cle 92 of the United Nations Charter identifies the Court as the principal
                      judicial organ of the United Nations and provides that its Statute —
                      annexed to the United Nations Charter — is an integral part of the
                      United Nations Charter. Article 36 (3) of the United Nations Charter pro-
                      vides that the Security Council “should also take into consideration that
                      legal disputes, as a general rule, be referred by the parties to the Interna-
                      tional Court of Justice”. It is thus clear that the Court is expected, through
                      its judicial function, to contribute to the maintenance of international
                      peace and security. Therefore, the discharge by the Court of its judicial
                      functions is not peripheral to, but is an integral part of the post‑World
                      War II system for the maintenance of international peace and security.
                         31. The law in this area should work to discipline States to refrain
                      from unlawful behaviour. Every State presenting a claim that another
                      State has breached Article 2 (4) of the United Nations Charter (that is not
                      patently unmeritorious or frivolous) deserves a decision as to whether, on
                      the basis of the relevant law and facts, that foundational provision has
                      been breached ; equally, the State against whom the claim is made needs
                      to know whether its acts breached Article 2 (4). It is therefore the Court’s
                      responsibility, as the “principal judicial organ of the United Nations”, to
                      take on the sometimes difficult and sensitive task of identifying the con-
                      tours of international law’s prohibition of the use of force 38.

                        36 For example, in the Military and Paramilitary Activities case, the Court noted that

                      Article 2 (4) :
                              “is frequently referred to in statements by State representatives as being not only a prin-
                              ciple of customary international law but also a fundamental or cardinal principle of such
                              law. The International Law Commission, in the course of its work on the codification of
                              the law of treaties, expressed the view that ‘the law of the Charter concerning the prohibi-
                              tion of the use of force in itself constitutes a conspicuous example of a rule in international
                              law having the character of jus cogens’ (paragraph (1) of the commentary of the Commis-
                              sion to Article 50 of its Draft Articles on the Law of Treaties, ILC Yearbook, 1966‑II,
                              p. 247).” (Military and Paramilitary Activities in and against Nicaragua (Nicaragua v.
                              United States of America), Merits, Judgment, I.C.J. Reports 1986, p. 100, para. 190.)
                         37 Article 33 of the UN Charter.
                         38 Article 92 of the UN Charter ; Military and Paramilitary Activities in and against
                      Nicaragua (Nicaragua v. United States of America), Jurisdiction and Admissibility, Judg‑
                      ment, I.C.J. Reports 1984, p. 435, para. 96: “It must also be remembered that, as the Corfu
                      Channel (United Kingdom v. Albania) case (I.C.J. Reports 1949, p. 4) shows, the Court has
                      never shied away from a case brought before it merely because it had political implications
                      or because it involved serious elements of the use of force.”

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                        32. This is a view that has been shared by former Members of the
                      Court. In his separate opinion in Oil Platforms, Judge Simma found it

                            “regrettable that the Court has not mustered the courage of restating,
                            and thus re‑confirming, more fully fundamental principles of the law
                            of the United Nations as well as customary international law (princi-
                            ples that in my view are of the nature of jus cogens) on the use of
                            force, or rather the prohibition on armed force, in a context and at
                            a time when such a reconfirmation is called for with the greatest
                            urgency” 39.
                         In 2005, Judge Elaraby criticized the Court’s decision in Armed Activi‑
                      ties on the Territory of the Congo (Democratic Republic of the Congo v.
                      Uganda) not to rule on the Democratic Republic of Congo’s claim that
                      Uganda’s acts amounted to aggression. In his view, it was part of the
                      Court’s “judicial responsibility” to determine whether Uganda’s acts met
                      the legal standard for aggression 40.

                        In the same case, Judge Simma also wondered why the Court was not
                      prepared to “call a spade a spade” when the Court refrained from making
                      a finding that Uganda’s military activities on Congolese territory were
                      not only violations of Article 2 (4) of the United Nations Charter but also
                      amounted to aggression 41.

                         33. The use of force among States has taken new forms, and entered
                      new arenas, since the San Francisco Conference in 1945. While the prohi-
                      bition of the use of force is a bedrock principle of the international legal
                      order, its edges are in need of further definition. It may even be worth
                      asking whether the ambiguity still present in the contours of the prohibi-
                      tion of the use of force damages respect for the norm. If so, this again
                      highlights the importance of the principal judicial organ of the United
                      Nations clarifying the contours of that prohibition when the opportunity
                      arises.
                         34. Consequently, in my view, the Court should only refrain from
                      making an express and discrete finding on a claim that the prohibition of

                         39 Oil Platforms (Islamic Republic of Iran v. United States of America), Judgment,

                      I.C.J. Reports 2003, separate opinion of Judge Simma, p. 327, para. 6.
                         40 Armed Activities on the Territory of the Congo (Democratic Republic of the Congo v.

                      Uganda), Judgment, I.C.J. Reports 2005, separate opinion of Judge Elaraby, p. 329,
                      para. 9 ; pp. 331‑332, para. 17.
                         41 In their opinions, both judges mention the relative functions of the Security Council

                      and the Court, and the Court’s role in resolving legal questions. Yet, as the citations show,
                      they still conclude that the Court should have been more explicit in its decisions on the use
                      of force (in Oil Platforms) and an act of aggression (in Armed Activities). Their words are
                      relevant in indicating a reluctance of the Court in recent times to determine certain issues
                      relating to the use of force.

                      155

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                      the use of force has been breached, if it is of the opinion that the claim is
                      patently unmeritorious or frivolous.

                                           D. Interpreting Paragraph 97

                         35. In paragraph 93, the Court found that the activities carried out by
                      Nicaragua in the disputed territory after 2010, including the excavation of
                      three caños and establishing a military presence in part of that territory,
                      constituted a breach of Costa Rica’s territorial sovereignty. The Court
                      further considers reparation for this breach in paragraphs 139 and 142. In
                      paragraph 97, the Court turns to Costa Rica’s claim that Nicaragua
                      breached the prohibition of the use of force. On this claim, the Court’s
                      position is that since it had already determined the unlawful character of
                      Nicaragua’s activities, there was no need to consider any further
                      Costa Rica’s submission that those activities breached the prohibition of
                      the use of force in Article 2 (4) of the United Nations Charter. As noted
                      earlier, the Court followed its decision in Cameroon v. Nigeria where the
                      Court finds that, “by the very fact of the present Judgment and the evac-
                      uation” of the disputed territory, the injury suffered by Costa Rica “will
                      in all events have been sufficiently addressed” (Judgment, I.C.J. Reports
                      2002, p. 452, para. 319).
                         36. The Court did not therefore make any discrete, express determina-
                      tion as to whether the prohibition of the use of force under Article 2 (4) of
                      the United Nations Charter had been breached. But it is not at all clear that
                      the Court has dispensed with any further consideration of Costa Rica’s
                      submissions relating to the use of force. A question arises as to the meaning
                      of the phrase “the injury suffered by Costa Rica”. The initial impression
                      might be that the finding is confined to the injury suffered by Costa Rica as
                      a result of the breach of its sovereignty and territorial integrity. The most
                      relevant feature of the “Judgment as a whole” is the Court’s finding that
                      Costa Rica has sovereignty over the disputed territory, that its territorial
                      sovereignty has been breached and the reparation awarded as a result. Yet,
                      the Court has deemed it unnecessary to rule on submissions relating to the
                      use of force because any injury suffered as a result of those allegations
                      would, in its view, be remedied. The sweeping phrase “in all events” sug-
                      gests a wider coverage and there would not seem to be any need for this
                      broader, all‑embracing phrase if “injury” were confined to a breach of sov-
                      ereignty and territorial integrity. I therefore interpret the phrase “the injury
                      suffered by Costa Rica” as encompassing any injury suffered by Costa Rica
                      as a result of a breach of the prohibition of the use of force.
                         37. If that is the correct interpretation, the question that arises is, how
                      does the Court determine the appropriate reparation for a breach of the
                      prohibition of the use of force without having first examined the claim
                      and decided that there was such a breach ? The obligation to make repa-
                      ration flows from a breach of an international obligation and the appro-
                      priate form and parameters of reparation are thus influenced by the fact

                      156

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                      of and circumstances of that breach 42. Further, while the appropriate
                      modality of reparation is determined by the circumstances 43, satisfaction,
                      by its very nature, relies upon some recognition of the fact of breach.

                         38. Moreover, can a breach of Article 2 (4) of the Charter, even if it is
                      not the most egregious breach, but nonetheless a breach of a provision
                      that is so fundamental to the maintenance of international peace and
                      security and to international relations as a whole that it constitutes
                      jus cogens, be remedied in the manner adopted by the Court ? The
                      approach by the Court in relation to a claim that “a cornerstone of the
                      United Nations Charter” 44 has been removed is, in the context of this
                      case, somewhat summary, dismissive and indiscriminate. The last sen-
                      tence of paragraph 97 is properly interpreted as referring to the Judgment
                      as a whole and the evacuation of the disputed territory as the factors that
                      sufficiently address the putative breach of the prohibition of the use of
                      force. Yet the term “Judgment as a whole” is vague and imprecise. In my
                      view, the finding that comes closest to reparation for that breach is the
                      finding of a breach of Costa Rica’s sovereignty and territorial integrity.
                      The paragraph also seems to proceed on the basis that, even if there is no
                      equivalence between the two norms, their relative values are such that a
                      breach of the prohibition of the use of force may be sufficiently remedied
                      by what flows from a finding of a breach of sovereignty and territorial
                      integrity. The Court’s conclusion in paragraph 97 suggests that it has
                      engaged in a comparative exercise. However, it is a conclusion that is
                      arrived at without any examination by the Court of the evidence relating
                      to the use of force.

                         39. While the Court’s jurisprudence establishes that the norms prohib-
                      iting the use of force and requiring respect for sovereignty and territorial
                          42 Paragraph 4 to the Commentary to Article 31 of the ILC’s Draft Articles on State

                      Responsibility 2001 states: “The general obligation of reparation is formulated in Article 31
                      as the immediate corollary of a State’s responsibility i.e., as an obligation of the responsible
                      State resulting from the breach, rather than as a right of an injured State or States . . .” And
                      as was famously stated by the Permanent Court of International Justice in the Factory at
                      Chorzów case (Factory at Chorzów, Jurisdiction, Judgment No. 8, 1927, P.C.I.J., Series A,
                      No. 9, p. 21): “It is a principle of international law that the breach of an engagement
                      involves an obligation to make reparation in an adequate form. Reparation therefore, is
                      the indispensable complement of a failure to apply a convention . . .”
                         43 See, e.g., the Court’s practice of a declaration of its findings as a form of satisfaction

                      laid down in the Corfu Channel case :

                                 “[T]o ensure respect for international law, of which it is the organ, the Court must
                              declare that the action of the British Navy constituted a violation of Albanian sover-
                              eignty.
                                 This declaration is in accordance with the request made by Albania through her
                              Counsel, and is in itself appropriate satisfaction.” (Corfu Channel (United Kingdom v.
                              Albania), Merits, Judgment, I.C.J. Reports 1949, p. 35.)
                         44   See footnote 32.

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                      integrity serve distinct functions, they reflect overlapping, but not identi-
                      cal, concerns 45. It is the element of the use of force that fundamentally
                      distinguishes the interests protected by Article 2 (4) of the United Nations
                      Charter from conduct that breaches sovereignty and territorial integrity
                      simpliciter. What the Court has done in its finding in the last sentence of
                      paragraph 97 requires some kind of weighing exercise leading to a conclu-
                      sion as to the relative values of the prohibition of the use of force against
                      territorial integrity and the relative values of the legal protection of sov-
                      ereignty and territorial integrity. But the Judgment offers no explanation
                      as to how this weighing exercise is carried out. In my view, a finding that
                      a country’s territorial sovereignty is breached should not, in the context
                      of this case, be used to provide reparation for a breach of Article 2 (4) of
                      the United Nations Charter.

                         40. The consequences of a breach of the norm prohibiting the use of
                      force will usually, or is much more likely to be far more calamitous than
                      a breach of the norm protecting sovereignty and territorial integrity sim‑
                      pliciter ; the first breach contains a greater risk of escalation posing a
                      threat to international peace and security. The overriding concern about
                      the use of force is that a powerful State may use it for its own advantage
                      and selfish purposes to the detriment of the international community.
                      This concern is well reflected in Corfu Channel where the Court spoke of
                      “the manifestation of a policy of force, such as has, in the past, given rise
                      to most serious abuses” 46. Of course, breaches of territorial integrity can
                      lead, and have in the past led to international conflicts. But the Court was
                      right to emphasize the very likely connection between a policy of force
                      and consequential calamitous abuses. In that case, the Court did not
                      accept the United Kingdom’s claim that it could, with the help of its mil-
                      itary, enter Albanian territorial waters to secure possible evidence of
                      Albania’s internationally wrongful conduct. Such a “right of interven-
                      tion”, the Court said, “would be reserved for the most powerful States,
                      and might easily lead to perverting the administration of international
                      justice itself ” 47. Similarly, and in general terms, the act of a country that
                      is militarily stronger than its neighbour claiming its neighbour’s territory
                      and placing troops thereon might easily lead to outright military confron-
                      tation, posing a threat to international peace and security.

                          45 Military and Paramilitary Activities in and against Nicaragua (Nicaragua v.

                      United States of America), Merits, Judgment, I.C.J. Reports 1986, p. 128, para. 251: “The
                      effects of the principle of respect for territorial sovereignty inevitably overlap with those of
                      the principles of the prohibition of the use of force and of non‑intervention.”
                         46    Corfu Channel (United Kingdom v. Albania), Merits, Judgment, I.C.J. Reports 1949,
                      p. 35.
                         47    Ibid.

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                                    E. The Determination of a Breach of Article 2 (4)
                                            of the United Nations Charter

                         41. As alluded to earlier, while the principle is a “cornerstone”, firmly
                      embedded in the legal order, there remains ambiguity in the parameters
                      of what amounts to a use of force. However, guidance regarding the rel-
                      evant factors to consider in determining a use of force can be drawn from
                      the Court’s jurisprudence. An appropriate legal analysis for the prohibi-
                      tion of the use of force considers the gravity of the acts and the purpose
                      that is reasonably deduced from the State’s actions and statements 48.

                         42. In the legal analysis it is important to maintain the distinction
                      between the rule protecting a State’s territorial sovereignty and the rule
                      prohibiting the use of force. Article 2 (4) of the United Nations Charter
                      prohibits the “threat or use of force against the territorial integrity . . . of
                      any state”. The Court’s finding that Costa Rica’s territorial integrity has
                      been breached, is, as explained above, entirely different from a finding
                      that a State has threatened or used force against the territorial integrity of
                      a State or the purposes of the United Nations Charter in breach of Arti-
                      cle 2 (4) of the United Nations Charter.

                        43. The Court’s jurisprudence establishes that the customary principle
                      of the non‑use of force and Article 2 (4) of the United Nations Charter
                      contain a threshold of force that needs to be surpassed for the legal
                      prohibition to be violated 49. The jurisprudence also establishes that

                      non‑violent use of force is not exempted from the prohibition 50. No shots
                      need be fired, no heavy armaments need be used and certainly no one
                      need be killed before a State can be said to have violated the prohibition.
                      Yet, the measures need to reach a certain gravity and have an unlawful
                      purpose before they cross the threshold and qualify as a use of force.

                         44. In assessing the placement of the relevant threshold for determining a
                      use of force, I agree with commentators who argue that “in its restriction to
                      armed or military force the prohibition must, however, be interpreted very
                      broadly to basically capture each and every form of armed force by indi-
                      vidual States” 51. This is in keeping with both the purpose of the norm to
                      maintain peace and security, as well as the foundational nature of the norm
                      in the current legal order.

                        48 For an analysis of examples drawn from the Court’s jurisprudence, see Olivier Corten,

                      The Law against War (Hart, 2010), particularly pp. 73 et seq.
                         49    Corfu Channel (United Kingdom v. Albania), Merits, Judgment, I.C.J. Reports 1949,
                      p. 35.
                         50 Ibid.
                         51 Oliver Dörr, “Use of Force, Prohibition of”, Max Planck Encyclopedia of Public
                      International Law, June 2011, para. 13.

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                        45. While an assessment of a State’s purpose is informed by gravity of
                      the acts, I analyse the facts of this case, as against the two criteria, sepa-
                      rately in the following section. This opinion argues that the gravity and
                      the purposes of Nicaragua’s activities attain the level of force prohibited
                      by Article 2 (4) of the United Nations Charter and the customary princi-
                      ple of the non‑use of force.

                                            (i) The Gravity of Nicaragua’s Actions
                         46. Article 2 (4) of the United Nations Charter prohibits the “threat or
                      use of force against the territorial integrity or political independence of
                      any state, or in any other manner inconsistent with the Purposes of the
                      United Nations”. The greater the use of force compromises the elements
                      of statehood or the purposes of the United Nations, the graver is the
                      breach of that norm.
                         47. In determining the applicability of gravity as a criterion for the
                      unlawfulness of the use of force under Article 2 (4) of the
                      United Nations Charter, it is helpful to advert to the 1974 United Nations
                      resolution on the Definition of Aggression (XXIX). The Preamble to the
                      1974 resolution characterized aggression as the “most serious and danger-
                      ous form of the illegal use of force” 52. Article 2 of the Definition provides
                      that a determination that an act of aggression has been committed would
                      not be justified if “the acts concerned or their consequences are not of
                      sufficient gravity”. A certain gravity therefore determines, not only the
                      existence of the use of force, but also the classification of that use of force.
                         48. Similarly, in Military and Paramilitary Activities in and against
                      Nicaragua (Nicaragua v. United States of America), the Court considered
                      the criterion of gravity to distinguish between an “armed attack” and a
                      “mere frontier incident” 53. It classified armed attack as the “most grave”
                      form of the use of force, but referred to “other less grave forms” of the
                      use of force 54, noting that an armed attack differed from other forms of
                      the use of force in terms of scale and effect. In considering what consti-
                      tuted an “armed attack”, the Court drew upon the Definition of Aggres-
                      sion in Article 3 (g) of resolution XXIX 55.

                         49. Assessing gravity is a case‑by‑case exercise, requiring the consider-
                      ation of such factors as, for example, location of the use of force, the state
                      of relations between the parties at the time, and other contextual factors,
                      etc. As was emphasized in the Court’s Advisory Opinion on the Legality
                      of the Threat or Use of Nuclear Weapons, the prohibition of the use of
                         52   Fifth preambular paragraph of the UN General Assembly resolution 3314 (1974).
                        53 Military and Paramilitary Activities in and against Nicaragua (Nicaragua v.

                      United States of America), Merits, Judgment, I.C.J. Reports 1986, pp. 103‑104, para. 195.
                        54 Ibid., p. 101, para. 191.
                        55 Ibid., p. 103, para. 195.

                      160

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                      force applies “regardless of the weapons employed” 56. The suggestion is
                      that a consideration of effect — and intended effect — are relevant to a
                      consideration of gravity, including (as noted in Nicaragua and quoted
                      above) for the characterization of the type of the use of force.

                         50. In this case, the factor that most clearly establishes gravity is the
                      prolonged presence of military camps and personnel on Costa Rican ter-
                      ritory — 11 weeks in 2010 to 2011 and nine months in 2013 57. The evi-
                      dence before the Court clearly establishes that both the camp close to the
                      first caño and the camp on the beach were manned by regular Nicaraguan
                      military personnel, not by the Nicaraguan police 58. Generally, a country’s
                      regular military personnel is seen as a greater coercive threat than its
                      police force. This military presence is a use of force “against the territorial
                      integrity” of Costa Rica, exactly the conduct prohibited by Article 2 (4)
                      of the United Nations Charter.

                         51. In the United Nations General Assembly resolution 2625 (XXV)
                      entitled “Declaration on Principles of International Law concerning
                      Friendly Relations and Co‑operation among States in Accordance with
                      the Charter of the United Nations” (the Friendly Relations Declaration),
                      which reflects customary international law 59, the General Assembly reit-
                      erated every State’s duty “to refrain from the threat or use of force to
                      violate the existing international boundaries of another State or as a means
                      of solving international disputes, including territorial disputes and prob-
                      lems concerning frontiers of States” (emphasis added). In the present
                      case, the Nicaraguan military was used to “violate the existing interna-
                      tional boundaries” of Costa Rica. The Court’s Judgment implicitly recog-
                      nizes that the boundaries established by today’s Judgment were those set
                      by the 1858 Treaty of Limits, as interpreted by the relevant Awards.
                      Equally, given that the location of the boundary was subject to a case
                      before the Court, to the extent that Nicaragua’s use of force may be seen
                      “as a means of solving international disputes”, it will violate the custom-
                      ary norm reflected in this duty.

                        52. Another index of the gravity of Nicaragua’s use of force is the
                      pointing of weapons, including what appears to be an anti-aircraft type

                         56 Legality of the Threat or Use of Nuclear Weapons, Advisory Opinion, I.C.J. Reports

                      1996 (I), p. 244, para. 39.
                         57 Supra at paras. 22, 23.
                         58 Supra at para. 19.
                         59 Military and Paramilitary Activities in and against Nicaragua (Nicaragua v. United

                      States of America), Merits, Judgment, I.C.J. Reports 1986, pp. 101‑103, paras. 191‑193 ;
                      Accordance with International Law of the Unilateral Declaration of Independence in Respect
                      of Kosovo, Advisory Opinion, I.C.J. Reports 2010 (II), p. 437, para. 80.

                      161

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                      missile at the Costa Rican aircraft on 1 November 2010 60. In the context
                      of a State’s military force already being stationed on another State’s ter-
                      ritory without the latter’s consent, the pointing of weapons is probative
                      of a use of force. It is a signal of its willingness to shoot when it considers
                      that to be necessary.

                        53. In conclusion, the facts before the Court establish that Nicaragua’s
                      actions were of sufficient gravity to warrant the application of Article 2 (4)
                      of the United Nations Charter and the customary principle of the non‑use
                      of force provided they are accompanied by the requisite purpose. It is to
                      that question that the opinion now turns.

                                                          (ii) Purpose
                        54. The second aspect of the analysis for an alleged breach of the pro-
                      hibition of the use of force is concerned with the purpose reasonably
                      deduced from a State’s actions, including their gravity, as well as state-
                      ments made by the State and the relevant context.

                         55. The first argument for the requirement of purpose is textual. Arti-
                      cle 2 (4) of the United Nations Charter prohibits the use of force “against”
                      the territorial integrity or political independence of any State or in any
                      other manner inconsistent with the purposes of the United Nations. It is
                      the ordinary meaning of the word “against” that clearly indicates the pur-
                      posive element in the Charter’s prohibition of the use of force. Absent
                      this element, there is no breach. The Concise Oxford Dictionary gives the
                      meaning of “against” as “in opposition to” or “to the disadvantage of”.
                      Put in more practical terms, the central question is whether a reasonable
                      interpretation of the evidence is that the purpose of the acts of the State
                      in question is to change the outcome of a matter with another State by
                      using force. In considering this qualification, it must be noted that the
                      drafters of the United Nations Charter did not intend to restrict the scope
                      of the prohibition by the specific mention of territorial integrity or politi-
                      cal independence, but rather to emphasize their protection 61.

                        56. When considering whether a State’s actions violate the prohibition
                      of the use of force, it is important to remember that: “[t]he essential fea-
                      ture which characterizes the prohibition of the use of force is the applica-

                         60  MCR, pp. 74‑75, para. 3.19.
                         61  Oliver Dörr, Albrecht Randelzhofer, “Chapter I Purposes and Principles,
                      Article 2 (4)”, in Bruno Simma, Daniel‑Erasmus Khan, Georg Nolte and Andreas Paulus,
                      (eds.), Nikolai Wessendorf (assistant ed.), The Charter of the United Nations : A Commen‑
                      tary, Vol. I, 3rd ed., Oxford University Press, 2012, pp. 215‑216.

                      162

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                      tion of military forces as a means of coercion . . .” 62. In this regard, I note
                      that the regular military forces of a State exist because of their coercive
                      abilities. An army is the symbol of a State’s coercive power, and, absent
                      consent, it will be a rare incident when the sending of its military forces
                      by one State to another does not evidence a coercive purpose.

                        57. In the first case to come before the Court, Corfu Channel, the Court
                      was presented with allegations that the United Kingdom had violated the
                      prohibition of the use of force. The situation in this case did not, in the
                      Court’s view, meet the threshold :
                               “[The Court] does not consider that the action of the British Navy
                            was a demonstration of force for the purpose of exercising political
                            pressure on Albania. The responsible naval commander, who kept his
                            ships at a distance from the coast, cannot be reproached for having
                            employed an important covering force in a region where twice within
                            a few months his ships had been the object of serious outrages.” 63

                      In its determination, the Court considered the evidence in light of the
                      purpose of the “demonstration of force” by the British Navy.

                         58. The Court’s case law considering allegations of an armed attack
                      also establishes that an appreciation of a State’s purpose is relevant to the
                      test for this form of the use of force. In Oil Platforms, the Court, in the
                      context of analysing whether certain actions, allegedly attributable to
                      Iran, would constitute an armed attack, explicitly considered relevant the
                      intention and purpose that could be deduced from the actions. It said :

                               “On the hypothesis that all the incidents complained of are to be
                            attributed to Iran, and thus setting aside the question, examined
                            above, of attribution to Iran of the specific attack on the Sea Isle City,
                            the question is whether that attack, either in itself or in combination
                            with the rest of the ‘series of . . . attacks’ cited by the United States
                            can be categorized as an ‘armed attack’ on the United States justify-
                            ing self‑defence. The Court notes first that the Sea Isle City was in
                            Kuwaiti waters at the time of the attack on it, and that a Silkworm
                            missile fired from (it is alleged) more than 100 km away could not have
                            been aimed at the specific vessel, but simply programmed to hit some
                            target in Kuwaiti waters. Secondly, the Texaco Caribbean, whatever
                            its ownership, was not flying a United States flag, so that an attack on
                            the vessel is not in itself to be equated with an attack on that State. As
                            regards the alleged firing on United States helicopters from Iranian
                         62 Oliver Dörr, “Use of Force, Prohibition of”, Max Planck Encyclopedia of Public

                      International Law, June 2011, para. 18.
                         63 Corfu Channel (United Kingdom v. Albania), Merits, Judgment, I.C.J. Reports 1949,

                      p. 35.

                      163

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                            gunboats and from the Reshadat oil platform, no persuasive evidence
                            has been supplied to support this allegation. There is no evidence that
                            the mine-laying alleged to have been carried out by the Iran Ajr, at a
                            time when Iran was at war with Iraq, was aimed specifically at the
                            United States ; and similarly it has not been established that the mine
                            struck by the Bridgeton was laid with the specific intention of harming
                            that ship, or other United States vessels. Even taken cumulatively, and
                            reserving, as already noted, the question of Iranian responsibility,
                            these incidents do not seem to the Court to constitute an armed attack
                            on the United States, of the kind that the Court, in the case concern-
                            ing Military and Paramilitary Activities in and against Nicaragua,
                            qualified as a ‘most grave’ form of the use of force . . .” 64 (Emphasis
                            added.)

                         59. In Military and Paramilitary Activities in and against Nicaragua
                      (Nicaragua v. United States of America), the Court considered that the
                      “possible motivations” driving a State’s use of force may be relevant for
                      a finding of an armed attack. It said :
                              “Turning to Honduras and Costa Rica, the Court has also stated . . .
                            that it should find established that certain transborder incursions into
                            the territory of those two States, in 1982, 1983 and 1984, were imput-
                            able to the Government of Nicaragua. Very little information is how-
                            ever available to the Court as to the circumstances of these incursions
                            or their possible motivations, which renders it difficult to decide
                            whether they may be treated for legal purposes as amounting, singly
                            or collectively, to an ‘armed attack’ by Nicaragua on either or both
                            States.” 65 (Emphasis added.)

                          60. The logic that makes a purposive analysis relevant for finding an
                      armed attack for the purposes of Article 51 of the United Nations
                      Charter applies equally to finding a use of force unlawful for purposes of
                       Article 2 (4) of the United Nations Charter. While the use of force may
                       often engage the international responsibility of a State, the United Nations
                       Charter itself recognizes that it may at times be lawful. Articles 42 and
                       51 of the United Nations Charter are to that effect. The end to which force
                       will be used, both in the context of Article 2 (4) and 51 of the United Nations
                       Charter, is therefore crucial in determining its legal status ; the inquiry
                       into the pursued end is nothing other than an analysis to discern the pur-
                       pose of the facts.
                         64 Oil Platforms (Islamic Republic of Iran v. United States of America), Judgment,

                      I.C.J. Reports 2003, pp. 191‑192, para. 64.
                         65 Military and Paramilitary Activities in and against Nicaragua (Nicaragua v.

                      United States of America), Merits, Judgment, I.C.J. Reports 1986, pp. 119‑120, para. 231.

                      164

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                         61. In this case, the question is whether the placement of Nicaraguan
                      military presence on the disputed territory can reasonably be interpreted
                      as action against Costa Rica in the sense that it was aimed at compromis-
                      ing its territorial integrity and political independence. Several pieces of
                      evidence lead to the conclusion that the long and repeated presence of
                      Nicaraguan military personnel on Costa Rican territory warrants that
                      interpretation ; it evidences the purpose of a State policy of the use of
                      force against Costa Rica.
                         62. The first item of evidence is the existence of a territorial dispute
                      between the Parties as soon as Costa Rica’s Government noticed the
                      Nicaraguan military presence and made its objections thereto known 66.
                      From 1 November 2010, Nicaragua was therefore on notice of Costa
                      Rica’s position, and any presence beyond that date is to be seen as an
                      action against the principal elements of statehood of that country — its
                      territorial integrity and political independence.

                         The second factor is the general history of hostilities and tense relation-
                      ship between the two States 67. When the evidence before the Court is
                      examined in the context of that history, it is reasonable to see the incur-
                      sions as acts against, that is, designed to compromise the principal ele-
                      ments of statehood of Costa Rica.

                         Third, Nicaragua’s initial refusal to withdraw the troops, both in
                      response to Costa Rica’s diplomatic Note and later, to the OAS resolu-
                      tion, also show the confrontational, if not hostile, use of its military pres-
                      ence and purpose to stand its ground.

                         Fourth, it is relevant that Nicaragua chose to increase its military pres-
                      ence near the first caño after Costa Rica had communicated its objec-
                      tions ; this is reasonably interpreted as a signal of that State’s readiness to
                      apply force, whenever Nicaragua considered it necessary 68.

                         Relatedly, and fifth, the establishment of a second camp in a different
                      location at a later stage again indicates a hardening of Nicaragua’s posi-
                      tion and is evidence of its purpose to defend the stance taken by force if
                      it considered that course necessary 69.
                         Sixth is the fact that both camps were established next to the caño‑
                      digging operations and therefore reasonably to be interpreted as protect-
                      ing another Nicaraguan policy directed against Costa Rica’s sovereign
                      interests.
                         Seventh, Nicaragua was using regular military forces, rather than irreg-
                      ular, unidentifiable personnel, or police forces. The signalling effect of

                        66 Supra at para. 13.
                        67 Supra at para. 12.
                        68 Supra at para. 18.
                        69 Supra at paras. 22‑24.

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                      using regular forces, which in general have a greater coercive potential
                      than police forces, is also to be seen not merely as confrontational, but as
                      evidence of its aim to challenge Costa Rica’s sovereign rights, by using
                      force, if it considered that course necessary.

                           Eighth, the second Nicaraguan military camp was on the disputed ter-
                        ritory and in breach of the Court’s provisional measures Order of
                        8 March 2011 70. This is an act of defiance which goes to the State’s pur-
                        pose and is to be contrasted with the situation at issue in Land and Mari‑
                        time Boundary (Cameroon v. Nigeria) on which the Court relies but in
                        which Nigeria’s military presence at the time of the proceedings was not
                        in contravention of an Order by the Court 71. This brazen violation of the
                      Court’s Order is perhaps the greatest indication of the unlawful aim
                      behind Nicaragua’s actions, showing as it does, that Nicaragua was
                      prepared to go as far as breaching an Order of the principal judicial organ
                       of the United Nations in order to maintain its claim to the disputed
                       territory.

                                                         F. Conclusion

                         63. The foregoing analysis leads to the conclusion that Nicaragua’s
                      activities were accompanied by the requisite gravity and purpose to war-
                      rant a finding of the use of force in breach of Article 2 (4) of the
                      United Nations Charter. It is for this reason that I am unable to join the
                      Court with respect to its conclusion in paragraph 229 (7).
                         64. One has to guard against the possibility that the Court’s approach
                      in this Judgment, together with the position it took in Land and Maritime
                      Boundary (Cameroon v. Nigeria) could be seen as developing a line of
                      jurisprudence in which it abstains from ruling on the merits of claims of
                      breaches of Article 2 (4) of the United Nations Charter in instances where
                      the acts complained of take place (at least in large part) on disputed ter-
                      ritory. In that regard, one notes and welcomes the salutary warning given
                      by the Court that “the fact that Nicaragua considered that its activities
                      were taking place on its own territory does not exclude the possibility of
                      characterizing them as an unlawful use of force” 72. If indeed a line of
                      jurisprudence is developing in which the Court abstains from ruling on

                         70 Certain Activities Carried Out by Nicaragua in the Border Area (Costa Rica v. Nica‑

                      ragua), Provisional Measures, Order of 8 March 2011, I.C.J. Reports 2011 (I), p. 27,
                      para. 86 (1): “Each Party shall refrain from sending to, or maintaining in the disputed
                      territory, including the caño, any personnel, whether civilian, police or security.”
                         71 Land and Maritime Boundary between Cameroon and Nigeria (Cameroon v. Nigeria :

                      Equatorial Guinea intervening), Judgment, I.C.J. Reports 2002, p. 451, paras. 312 and 314 ;
                      p. 457, para. 325 (V) (A).
                         72 See paragraph 97 of the Judgment.

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                      the merits of claims of the use of force in a disputed territory, this course
                      is to be regretted. Disputed territories are one of the most sensitive cat
                      egories of international relations and particularly prone to provoking the
                      use of force by States. A judicial practice of ruling on the merits of every
                      claim by a State that another State has breached Article 2 (4) of the
                      United Nations Charter would be entirely consistent with, and supportive
                      of the system established after World War II for the maintenance of inter-
                      national peace and security and the Court’s role in that system. Both
                      Applicant and Respondent will learn valuable lessons for their future
                      conduct from the Court’s ruling. Indeed, the international community as
                      a whole will profit from this judicial practice. It is reiterated that the argu-
                      ment is not that the Court must rule on the merits of every claim made by
                      a State, but rather that the centrality of Article 2 (4) of the Charter in
                      modern international relations requires the Court to determine the merits
                      of a claim of a breach of the prohibition of the use of force, unless it is
                      patently unmeritorious or frivolous.

                         65. Nothing in this opinion is to be seen as taking a position that
                      devalues the legal prohibition of the use of force or as taking the prover-
                      bial sledgehammer to kill a flea. International law has a spectrum of
                      activities that may breach Article 2 (4) of the United Nations Charter at
                      its higher, middle and lower reaches ; some of the activities at the higher
                      reaches may amount to aggression, “the most serious and dangerous
                      form of illegal use of force” 73; others may constitute an armed attack giv-
                      ing rise to self‑defence. Activities at the middle and lower reaches may
                      also breach Article 2 (4) of the United Nations Charter if they are accom-
                      panied by the requisite gravity and purpose ; such activities may very well
                      be what the Court had in mind in Paramilitary Activities when it referred
                      to “other less grave forms of the use of force” 74. The presence of grad
                      ations in the law relating to the use of force responds to the concern that
                      a finding that activities at the middle or lower end of the spectrum, if
                      accompanied by the requisite gravity and purpose, constitute a breach of
                      Article 2 (4) of the United Nations Charter, would somehow discredit the
                      seriousness of the international obligations involved.

                         66. In order to determine the rules applicable to those “less grave
                      forms of the use of force” the Court, after emphasizing the customary
                      status of the Friendly Relations Declaration, went on to cite a number of
                      duties set out in the declaration. Included in the Court’s list, as already

                        73   International Criminal Court, RC/Res. 6, Ann. III, Understanding No. 6.
                        74   See footnote 54.

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                      stated 75, is “the duty to refrain from the threat or use of force to violate
                      the existing international boundaries of another State or as a means of
                      solving international disputes, including territorial disputes and concern-
                      ing frontiers of States”. It is precisely this duty that Nicaragua breached
                      when it placed its soldiers on Costa Rican territory.

                         67. In my view, a State placing members of its military force on the
                      territory of another State on two occasions for a combined period of
                      about one year over a three‑year period is a breach of the norm prohibit-
                      ing the use of force. These activities by Nicaragua certainly cannot be
                      characterized as a “mere frontier incident” of the kind referred to by the
                      Court in Military and Paramilitary Activities in and against Nicaragua
                      (Nicaragua v. United States of America) 76. The presence of a military
                      force for such a long period without the consent of the other State consti-
                      tutes, by itself, a breach of Article 2 (4) of the United Nations Charter.
                      This action could certainly have led to a military conflict between Nicara-
                      gua and Costa Rica and posed a threat to international peace and secu-
                      rity, warranting the intervention of the Security Council, had Costa Rica
                      not exercised commendable restraint and chosen to have recourse to the
                      Court rather than to respond in kind. Nicaragua by its military presence
                      excluded Costa Rica from its own territory by staking a claim to territory
                      that had been determined from 1858 in the Treaty of Limits to be
                      Costa Rican, and which Nicaragua had never claimed as its own until
                      26 November 2010 after Costa Rica had filed its Application before the
                      Court on 18 November 2010. While not at the higher reaches of the spec-
                      trum, Nicaragua’s acts are certainly not at the lower end ; they are some-
                      where in between. Arguably, the prolonged presence of Nicaragua’s
                      forces on Costa Rican territory signifies that Nicaragua’s acts are not at
                      the lower end of the spectrum.

                         68. In my view, since the affront to Costa Rica is aggravated by the
                      prolonged Nicaraguan military presence on Costa Rican territory, par-
                      ticularly so in the nine‑month period after the Court ordered Nicaragua
                      to remove its soldiers, it would be appropriate to consider an apology as
                      satisfaction.
                         69. It is not clear from the evidence how many soldiers were actually
                      placed by Nicaragua in the disputed territory. What is certain, however,
                      is that the military presence was sufficiently substantial to have been
                      described by Costa Rica and acknowledged by Nicaragua as “a military
                      encampment” 77 and notably, in its Order for provisional measures of
                      22 November 2013, the Court found that the photograph dated 5 Febru-

                        75 Supra at para. 51.
                        76 Military and Paramilitary Activities in and against Nicaragua (Nicaragua v.
                      United States of America), Merits, Judgment, I.C.J. Reports 1986, p. 104, para. 195.
                        77 Paragraph 125 of the Judgment.

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                      ary 2013 did show a “Nicaraguan army encampment” 78. The fact that the
                      Nicaraguan force may not have been constituted by a very large number
                      of soldiers does not in any way detract from the characterization of Nica-
                      ragua’s conduct as an unlawful use of force in contravention of Arti-
                      cle 2 (4) of the Charter. Generally, the size of a military force deployed
                      will depend upon a variety of factors, including the purpose of the deploy-
                      ment, the characteristics of the particular location and a State’s military
                      capability, including the number of troops at its disposal.

                        70. It is recalled that while the means employed in using force is rele-
                      vant in determining gravity and therefore, lawfulness, it is not conclusive ;
                      the effect of the means must also be considered. In this case, the number
                      of soldiers deployed by Nicaragua was sufficient to achieve its unlawful
                      ends : it was able to remain on Costa Rican territory for a period of about
                      one year over a three‑year period in order to further its policy.

                         71. The years since the adoption of the United Nations Charter have
                      only served to re‑emphasize the importance to the international legal
                      order, of Article 2 (4) and its customary equivalent. The Court should
                      play its role in upholding and applying the prohibition, adjudicating
                      claims that the norm has been breached, unless the claim is patently
                      unmeritorious or frivolous.

                                                                            (Signed) Patrick Robinson.

                        78   See supra para. 24 and footnote 31 of this opinion.

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