Territorially Intrusive Intelligence Collection and International Law

[Commander Roger D. Scott\*]{.smallcaps}

# I. INTRODUCTION

A recurring question regarding operational law is whether surreptitious
spying in another nation's territory is "illegal." The cases raising
this question involved no sabotage or other destructive acts, but simply
the collection of information through various surreptitious, intrusive
means inside a foreign nation's territory without that nation's
knowledge or consent. Several highly classified legal reviews of such
intelligence collection operations, performed at the highest levels in
the Department of Defense, stated essentially that the operations were
illegal and were undertaken at the risk of the personnel or units
involved.[^1] This nonsupportive, almost hand-washing kind of approach
fails to state exactly what law such spying violates. While possible
answers include United States domestic law, international law, or the
law of the target nation, a close analysis does not support any of
these.

United States domestic law does not prohibit nondestructive,
surreptitious intelligence collection and, in fact, affirmatively
supports it.[^2] The United States is not a party to any treaty or
agreement that prohibits surreptitious, nondestructive intelligence
collection. Such intelligence collection also does not violate customary
international law. In fact, customary international law has evolved such
that spying has become the long-standing practice of nations. Indeed,
while the surreptitious penetration of another nation\'s territory to
collect intelligence in peacetime potentially conflicts with the
customary principle of territorial integrity, international law does not
specifically prohibit espionage.

Conversely, surreptitious intelligence collection in another nation's
territory probably violates the target nation's domestic law just as
espionage against the United States violates United States domestic
law.[^3] However, the fact spying on other countries violates their law
is far different from the assertion that the activity itself is illegal,
as if some skulking shame of criminality were attached to the
enterprise. Our spies are patriots. They take the risk of target country
detection and punishment for espionage as a basic tenet of their trade,
but the United States is under no legal obligation, domestic or
international, to refrain from engaging in espionage. High levels of
security classification for information relating to espionage operations
are appropriate to help ensure the success of the operations, but not
because we need to cloak illegal activity in code words while we wink
and nod in furtive staffing conspiracies.

No international convention has ever addressed the legality of peacetime
espionage. Indeed, espionage has been practiced by the nations of the
world for centuries. Individual states have, however, enacted laws that
severely punish espionage against their own interests. The law of
espionage is, therefore, unique in that it consists of a norm
(territorial integrity), the violation of which may be punished by
offended states, but states have persistently violated the norm,
accepting the risk of sanctions if discovered. This article addresses
the issues surrounding the question whether international law prohibits
espionage. It first explores whether principles of customary law
prohibit such acts. Next, this article addresses peacetime espionage and
the principles of unlawful intervention in the affairs of sovereign
nations. Finally, it examines the interaction of peacetime espionage and
the inherent right to self-defense.

**II. No Principle of *Jus Cogens* Against Espionage**

The international community recognizes some principles of international
law as so fundamental that they constitute peremptory norms. Such
principles, referred to as *jus cogens*, prevail over international
agreements and other principles of international law in conflict with
them.[^4] Espionage is not prohibited by international law as a
fundamentally wrongful activity; it does not violate a principle of *jus
cogens*. The law of war recognizes the well-established practice of
employing spies.[^5] Resort to that practice involves no violation of
the laws of war, though spies may be harshly punished when captured by
belligerents. Spies caught behind enemy lines during armed conflict are
not entitled to treatment as prisoners of war and may be put to death,
but under international law they are entitled to a trial.[^6] A spy who
successfully accomplishes his mission and returns to his own lines may
not be tried as a spy upon subsequent capture.[^7] In addition to the
specific acknowledgement of espionage in the law of war, intelligence
gathering in peacetime from outer space and from the high seas is
clearly permitted under international law.[^8]

# III. Peacetime Espionage and 

# Unlawful Intervention

The conduct of espionage inside the territory of another nation during
peacetime is treated differently. The respect of each sovereign for the
territorial integrity and political independence of others is a basic
principle of international law.[^9] The traditional doctrinal view is
that intelligence gathering within the territory of other states during
peacetime constitutes an unlawful intervention.[^10] The essence of the
international law norm against peacetime espionage is the lack of
respect for the territorial boundaries of another sovereign, including
national airspace, internal waters, and territorial seas.[^11]
Notwithstanding the apparent clarity of the traditional view, espionage
is not prohibited by any international convention because all states
have an interest in conducting such activity.

Hays Parks, a national security law expert, described the fundamentally
self-interested nature of domestic espionage law in the following
manner:

Each nation endeavors to deny intelligence gathering within its
territory through domestic laws . . . . Prosecution under domestic law
(or the threat thereof) constitutes a form of denial of information
rather than the assertion of a *per se* violation of international law;
domestic laws are promulgated in such a way to deny foreign intelligence
collection efforts within a nation\'s territory without inhibiting that
nation\'s efforts to collect intelligence about other nations. No
serious proposal has ever been made within the international community
to prohibit intelligence collection as a violation of international law
because of the tacit acknowledgement by nations that it is important to
all, and practiced by each.[^12]

A review of the espionage laws of the United States[^13] aptly
illustrates the point that national laws designed to defend national
interests against foreign espionage generally do not prohibit espionage
against other nations. These laws forbid activity that would facilitate
the use of United States national defense information to the prejudice
of the United States or to the advantage of any foreign power, but they
do not prohibit United States espionage against other nations. In fact,
many other United States laws are designed to facilitate foreign
intelligence collection by exempting such activity from laws that would
impose inconsistent burdens. For example, the Fiscal Year 1991
Intelligence Authorization Act provided the Secretary of Defense new
authority to establish and operate overseas \"proprietaries,\" or
commercial \"covers,\" for military intelligence activities.[^14] Under
the new law, activities associated with commercial covers, including for
example, falsification of official records, enjoy the sovereign immunity
of the United States. Other nations have similar laws promoting national
espionage but prohibiting foreign espionage.

International law develops from the practice of nations. The
long-standing state practice of deviation from the norm of
nonintervention in sovereign territory by spying creates the dilemma for
international law. International law must sustain a fundamental norm
against a tidal wave of contrary state practice. An \"espionologist\"
could devote a lifetime to documenting both the prevalence of peacetime
spying throughout history and the punishment of captured foreign
spies.[^15] This dilemma has led some prominent jurists to conclude that
peacetime espionage does not violate international law. According to
Lauterpacht\'s edition of *Oppenheim*:

Spies are secret agents of a state sent abroad for the purpose of
obtaining clandestinely information in regard to military or political
secrets. Although all states constantly or occasionally send spies
abroad, and although it is not considered wrong morally, politically, or
legally to do so, such agents have, of course, no recognized position
whatever according to international law, since they are not agents of
states for their international relations. Every state punishes them
severely when they are caught committing an act which is a crime by the
law of the land, or expels them if they cannot be punished. A spy cannot
be legally excused by pleading that he only executed the orders of his
government and the latter will never interfere, since it cannot
officially confess to having commissioned a spy.[^16]

Professor Quincy Wright, however, vigorously resists the notion that
spying has become legal through constant practice. It is, he argues, a
consistently practiced illegal activity.[^17] By contrast, the Yale
scholars, McDougal, Lasswell, and Reisman, perceive, in the toleration
of peacetime spying, \"a deep but reluctant admission of the lawfulness
of such intelligence gathering, when conducted within customary
normative limits.\"[^18] The \"New Haven School\" views information
gathering as necessary to reduce international friction and to guard
against surprise.[^19] As long as the world remains divided and hostile,
special measures to gather secret information from closed societies are
necessary to maintain world public order.[^20] Such measures, however,
would not be justified if they were so intrusive or offensive as to
threaten the internal order of a state in which they were employed.[^21]
Presumably, fidelity to such customary norms would preclude the use of
torture, drugs, or murder. Given this variety of views, the status of
espionage under international law remains ambiguous, not specifically
permitted or prohibited.

Notwithstanding the prevalence of espionage, however, it is doubtful
that espionage in another nation\'s territory will ever be explicitly
acknowledged as \"legal\" under the law of nations. International law
continues to support the existence of a territorial integrity norm with
which espionage potentially conflicts, but even the nature of such a
potential conflict remains ambiguous. International law has left
enforcement against espionage entirely to the discretion of offended
states. Individual states do not treat different forms of espionage by
different countries in the same way. France has expelled suspected
United States agents, while North Korea has detained them. The treatment
of espionage is a matter of the domestic regulatory discretion inherent
in sovereignty and is a part of the risk inherent in espionage activity.

# IV. Peacetime Espionage and 

# the Right of Self-Defense

Particular forms of espionage, for example by ships, submarines, or
aircraft, may raise issues of national self-defense instead of issues of
domestic criminal law. Examples of nations treating particular forms of
espionage as armed aggression include the following incidents: the shoot
down of U-2s on United States or Taiwanese missions over China and the
former Soviet Union in the late 1940s and the 1950s,[^22] the Soviet
shoot down of the civilian airliner KAL 007,[^23] the shouldering of the
Yorktown and the Caron in the Black Sea off the coast of the former
Soviet Union,[^24] the North Korean attack upon the U.S.S. Pueblo,[^25]
and the Swedish government's use of depth-charges against Soviet
submarines in Sweden\'s territorial sea.[^26] The Charter of the United
Nations recognizes the right to use force in national or collective
self-defense against armed aggression.[^27] Nations perceive the threat
of armed aggression differently, and international law has not attempted
to codify precisely the circumstances that justify the use of force in
self-defense. Accordingly, particular forms of espionage may give rise
to the use of force as well as a response under domestic criminal law.
This is an added risk of espionage particularly applicable to ships and
aircraft.

The right of self-defense may also justify the collection of
intelligence. Intelligence is necessary to give substance and effect to
the right of self-defense, including the customary international law
right of anticipatory or peremptory self-defense. Appropriate defensive
preparations cannot be made without information about potential threats.

The Charter of the United Nations prohibits the use of force in
international relations,[^28] but preserves the \"inherent right of
individual or collective self-defense.\"[^29] In other words, force may
not be used aggressively, but it may be used defensively. Scholars have
argued over the scope of the right of self-defense, but there is no
question that the United States has exercised it vigorously, including
the right of anticipatory or peremptory self-defense.[^30] Given the
destructiveness of modern weapons, it may be too late to wait for the
enemy to strike the first blow. The need for intelligence to support
effective exercise of the right of anticipatory self-defense is greater
in today\'s friction-filled, multipolar world than it has ever been
before.

Surreptitious intelligence collection will never be noticed if it is
successful. It is a minimal intrusion, and evidence of an international
norm against intelligence collection on foreign territory is weak.
Indeed, if such a norm exists, it may be a norm more honored in the
breach. Accordingly, the surreptitious collection of intelligence in the
territory of other nations that present clear, articulable threats based
on their past behavior, capabilities, and expressions of intent, may be
justified as a practice essential to the right of self-defense. Examples
of incipient threats that cannot be effectively countered without the
assistance of intelligence are the proliferation of weapons of mass
destruction and state supported terrorism.[^31]

In an era plagued by the threat of terrorism, the proliferation of
weapons of mass destruction,[^32] rogue sovereigns, and new threats not
previously contemplated by international law,[^33] where hostile, closed
societies will not participate in international arms control efforts or
confidence and security building measures, the need for intelligence is
still as compelling as it was during the Cold War. Explaining the U-2
program after Gary Powers was shot down over the Soviet Union, President
Eisenhower said on national television that \"\[n\]o one wants another
Pearl Harbor. This means we must have knowledge of military forces and
preparations around the world, especially those capable of massive
surprise attack.\"[^34] In a statement made two days before the
President\'s message to the nation, Secretary of State Herter explained:

> In accordance with the National Security Act of 1947, the President
> has put into effect since the beginning of his administration
> directives to gather by every possible means the information required
> to protect the United States and the free world against surprise
> attack and to enable them to make effective preparations for their
> defense.[^35]

Similarly, no one wants another invasion of Kuwait, another Khobar
Towers,[^36] another World Trade Center bombing,[^37] or a regional
nuclear war between secret nuclear powers.[^38] To the extent
intelligence collection makes it possible for the United States, or any
other nation, to prevent such incidents, the use of international
espionage as instrument of self-defense seems justified.

# V. Summary and Conclusion

As a general principle, territorially intrusive intelligence collection
by United States agents is not illegal under United States or
international law. No treaties or other sources of international law
specifically prohibit espionage. International law does require respect
for the territorial integrity of other states, but states have practiced
territorially intrusive intelligence collection by air, sea, and on
land, through a variety of means, from time immemorial. The domestic law
of almost every state promotes the territorially intrusive collection of
foreign intelligence by its own agents. As long as unexpressed but
generally accepted norms and expectations associated with espionage are
observed, international law tolerates the collection of intelligence in
the territory of other nations. However, international law also
recognizes the authority of penetrated states to apply their domestic
law to agents and instruments of a foreign power caught collecting
intelligence within their boundaries. Different states have different
policies toward the interdiction and punishment of foreign agents caught
within national boundaries. The domestic law of most states proscribes
such activity; some states have even executed suspected foreign agents
without a trial. The legal status of foreign intelligence collection is,
therefore, a classic double standard--states prohibit espionage against
themselves, but they do it to others. In this contest for information
between states, international law still stands ambiguously aloof,[^39]
but the record of state practice is clear--espionage is traditional
state activity. The international community might never explicitly
recognize territorially intrusive espionage as legal under international
law, but there are at least strong arguments against our own lawyers
treating their clients' intelligence activity as illegal.

[^1]: **\*** *Commander Scott (B.A., Mary Washington College; M.A.,
    Naval War College; J.D. & LL.M., The University of Virginia School
    of Law) is the Assistant Legal Advisor, United States European
    Command, Patch Barracks, Vaihingen, Germany. He is a member of the
    Virginia State Bar.*

    ^?^ Interview with Representatives of the Office of Senior Deputy
    General Counsel (International Affairs and Intelligence), Department
    of Defense, in Arlington, Virginia (March 1995). Of course, the
    documents cannot be cited specifically due to their classified
    status. However, the reader may contact the author for further
    information concerning the documents.

[^2]: *See infra* note 13 and accompanying text.

[^3]: For a good introduction to espionage crimes against the United
    States, see Major Carol A. DiBattiste, *Air Force Espionage: Two
    Recurring Issues,* [32 A.F. L. Rev.]{.smallcaps} 377 (1990).

[^4]: [Rest. (Third) of the Foreign Relations Law of the United
    States]{.smallcaps} § 102 cmt. k (1995). *See also* [John Norton
    Moore et al]{.smallcaps}., [National Security Law]{.smallcaps} 68
    (1990).

[^5]: Instructions for the Government of the Armies of the United States
    in the Field, Headquarters, United States Army, Gen. Order No. 100,
    art. 88(1) (Apr. 24, 1863) \[the Lieber Code\], *in* [The Laws of
    Armed Conflicts]{.smallcaps} 3 (Dietrich Schindler & Jiri Toman
    eds., 3d ed. 1988); Hague Convention No. IV Respecting the Laws and
    Customs of War on Land and Annex Thereto, arts. 29-31, Oct. 18,
    1907, 36 Stat. 2277, 1 Bevans 631, *in* [The Laws of Armed
    Conflicts]{.smallcaps}, 63 (Dietrich Schindler & Jiri Toman eds., 3d
    ed. 1988) \[hereinafter Hague Convention No. IV\]. "Spying does not
    violate the law of war. 'Spies are punished not as violators of the
    law of war, but to render that method of obtaining information as
    dangerous, difficult, and ineffective as possible.'" United States
    Army Judge Advocate General's School, [Operations Law
    Handbook,]{.smallcaps} at 17-5 (1997).

[^6]: Hague Convention No. IV, *supra* note 4, art. 30. *See* Protocol
    Additional to the Geneva Conventions of 12 Aug. 1949, and Relating
    to the Protection of Victims of International Armed Conflicts
    (Additional Protocol I), arts. 39(3), 46, 1125 U.N.T.S. 3, 16 I.L.M.
    1391 (1977) (recognizing existing international law applicable to
    espionage during armed conflict).

[^7]: Hague Convention No. IV, *supra* note 4, art. 31. *See* [Green
    Hayward Hackworth, Digest of International Law]{.smallcaps} § 581,
    at 304-06 (1943).

[^8]: [J. Brierly, The Law of Nations]{.smallcaps} 59-61 (H. Waldock
    ed., 6th ed. 1984). *See* Oliver J. Lissitzyn, *Electronic
    Reconnaissance from the High Seas and International Law*, *in* 61
    [U.S. Naval War Coll. Int. L. Studies,]{.smallcaps} 1947-1977, at
    563, 567 (R. Lillich & J. Moore eds., 1980); Julius Stone, *Legal
    Problems of Espionage in Conditions of Modern Conflict*, *in*
    [Essays on Espionage and International Law]{.smallcaps} 29, 34
    (Roland J. Stranger ed., 1962).

[^9]: 5 [M. Whiteman, Digest of International Law]{.smallcaps} 183
    (1965); 1 [L. Oppenheim\'s International Law]{.smallcaps} 288 (H.
    Lauterpacht ed., 8th ed. 1955) (\"A State is not allowed to send its
    troops, its men-of-war, or its police forces into or through foreign
    territory . . . without permission.\"). *See* Quincy Wright, *Legal
    Aspects of the U-2 Incidents*, 54 [Am. J. Int\'l L.]{.smallcaps} 836
    (1960) \[hereinafter Wright, *U-2 Incidents*\]. The principle of
    territorial integrity is recognized in article 2(4) of the United
    Nations Charter, but the Charter only prohibits \"the threat or use
    of force against the territorial integrity or political independence
    of any state.\" U.N. Charter art. 2, para. 4. It does not prohibit
    every trespass. Wright, *U-2 Incidents, supra,* at 844.

[^10]: Quincy Wright, *Espionage and the Doctrine of Non-Intervention in
    Internal Affairs*, *in* [Essays on Espionage and International
    Law]{.smallcaps} 3 (Roland J. Stranger ed., 1962) \[herinafter
    Wright, *Espionage*\]; Myres S. McDougal et al[.,]{.smallcaps} *The
    Intelligence Function and World Public Order*, 46 [Temp.
    L.Q.]{.smallcaps} 365, 394 (1973) \[hereinafter McDougal, *World
    Public Order*\].

[^11]: Wright, *Espionage*, *supra* note 10, at 2-12. *See also* Wright,
    *U-2 Incidents*, *supra* note 9, at 845 (concerning airspace);
    Ingrid Delupis, *Foreign Warships and Immunity for Espionage*, 78
    [Am. J. Int\'l L.]{.smallcaps} 53, 67-69 (1984) (concerning internal
    waters and territorial seas).

[^12]: W. Hays Parks, *The International Law of Intelligence
    Collection*, *in* [National Security Law]{.smallcaps} 433-34 (John
    Norton Moore et al. eds., 1990).

[^13]: 18 U.S.C. §§ 792-798 (1976 & Supp. 1985).

[^14]: These provisions have been codified at 10 U.S.C. §§ 431-437
    (1990) (\"Authority to engage in commercial activities as security
    for intelligence collection activities.\"). Explaining the purpose
    for this new legislation, the Report of the Senate Select Committee
    on Intelligence stated that, \"intelligence elements of the
    Department of Defense that carry out intelligence collection
    operations abroad currently lack the statutory authority to
    establish cover arrangements, similar to the \[Federal Bureau of
    Investigation\] and \[Central Intelligence Agency\], that would
    withstand scrutiny from the internal security services of foreign
    governments . . . .\" [S. Rep]{.smallcaps}. No. 102-85, 101^st^
    Cong., 2d Sess. (1991), 8 U.S.C.C.A.N. 193, 216 (1991).

[^15]: There are a number of famous examples. Sending twelve spies into
    Canaan, Moses had them \"see what the land is like: whether the
    people who dwell in it are strong or weak, few or many . . . whether
    the cities they inhabit are like camps or strongholds . . . .\"
    *Numbers* 13:17-25. The date for the sailing of the Spanish Armada
    was provided to Sir Francis Walsingham by the spy Ousley in a wine
    cask shipped back to England from the port of Malaga. [Allison Ind,
    A Short History of Espionage]{.smallcaps} 29 (1963). Elizabethan
    England\'s knowledge of the threat posed by Philip II\'s Spain came
    principally from its intelligence network. Christopher Andrew, *The
    Nature of Military Intelligence*, *in* [Go Spy the Land]{.smallcaps}
    1-2 (Keith Neilson & B.J.C. McKercher eds., 1992). Intelligence
    specialists in Poland, France, and Great Britain attempted to break
    the German ULTRA/ENIGMA code from 1925-1938 during the Nazi military
    buildup. Poland\'s early success depended on a copy of instructions
    for the modified ENIGMA machine which were provided by a spy. Linda
    Yolande Gouaze, [Needles and Haystacks: The Search for ULTRA in the
    1930s]{.smallcaps} 20-35 (1983) (Naval Post Graduate School thesis,
    published by the Defense Technical Information Center). The Soviet
    Union engaged in extensive overseas intelligence activity during the
    Cold War, including signal intelligence (SIGINT) activities at its
    diplomatic facilities all over the world, the use of disguised
    trucks and vans equipped for SIGINT collection (including one Czech
    truck which toured the United States from 17 July to 2 December
    1987), the use of naval auxiliary ships equipped for SIGINT
    collection (these vessels periodically entered United States
    territorial seas), and the use of individual agents to collect human
    intelligence. [Desmond Ball, Soviet Signals
    Intelligence]{.smallcaps} 38, 45, 70-80, 95-100, 126, 134 (1989).
    Cases of Soviet spies discovered in Western countries are too
    numerous and well-known to rehearse in detail, but among them is the
    case of Conon Molody (alias Gordon Arnold Lonsdale). Exposed in
    England when his carefully constructed cover as a Canadian citizen
    fell apart for inattention to the detail of circumcision, which,
    according to medical records, had been performed on the real infant
    Lonsdale. *See* [Allison Ind, A Short History of
    Espionage]{.smallcaps} 274-76 (1963). Other famous spies for the
    Soviet Union included Rudolf Abel, Klaus Fuchs, and the Rosenbergs.
    [G.J.A. O\'Toole, The Encyclopedia of American Intelligence and
    Espionage]{.smallcaps} 1-2, 395-96 (1988). Incidents of United
    States Cold War espionage include the Berlin Tunnel (Project Gold),
    which tapped Soviet and East German telephone and teletype networks,
    and U-2 flights over the Soviet Union and Cuba. *Id*. at 66-68, 230,
    458-60. Espionage continues unabated after the end of the Cold War.
    Regarding economic espionage against United States firms by allies,
    see generally [Peter Schweizer, Friendly Spies]{.smallcaps} (1993);
    Ronald Ostrow, *Economic Espionage Poses Major Peril to U.S.
    Interests*, [L.A. Times]{.smallcaps}, Sept. 28, 1991, at A1.
    McDougal and Feliciano note that espionage and counterespionage
    activities are conducted throughout the territories of belligerents
    and non-belligerents during armed conflict. [Myres S. McDougal &
    Florentino Feliciano, Law and Minimum World Public
    Order]{.smallcaps} 559 (1961). France recently expelled five
    American agents for political, economic, and industrial espionage.
    Suzanne Lowry & Hugh Davies, *France Expels Five Americans on Spy
    Charges*, [Daily Tel.]{.smallcaps}, Feb 23, 1995, at 11. Antonin
    Scalia, serving as an Assistant Attorney General in 1975, authored a
    classified memorandum of law on spying against foreign embassies,
    finding the practice so widespread that general language in the
    Vienna Convention on Diplomatic Relations on the "inviolability" of
    embassies should not be read as prohibiting such activities. Antonin
    Scalia, Assistant Attorney General, Office of Legal Counsel,
    Memorandum for the Attorney General on The Vienna Convention (Dec.
    24, 1975).

[^16]: 1 [L. Oppenheim's International Law]{.smallcaps} § 455, at 862
    (H. Lauterpacht ed., 8th ed. 1955). By \"recognized position,\"
    Oppenheim refers to diplomatic or consular status, visiting armed
    forces, or status as an individual foreign guest or visitor with
    host nation permission. International law has not defined the
    \"status\" of spies. In the case of a diplomat, article 9 of the
    Vienna Convention on Diplomatic Relations clarifies the status of
    diplomatic immunity and recognizes expulsion by the host state as
    the correct remedy for diplomats caught spying. *See* [Diplomatic
    Law: A Commentary on the Vienna Convention on Diplomatic
    Relations]{.smallcaps} 40-44 (1976); Jonathan Brown, *Diplomatic
    Immunity: State Practice Under the Vienna Convention on Diplomatic
    Relations*, 37 [Int\'l & Comp. L.Q.]{.smallcaps} 53-88 (1988).
    Similar to diplomatic immunity, warships and auxiliaries have long
    enjoyed sovereign immunity. As reflected in the United Nations Law
    of the Sea Convention (article 32), sovereign immune vessels caught
    engaging in activities inconsistent with \"innocent passage\" in
    foreign waters, such as spying, are obliged to comply with host
    nation demands that such vessels depart. *See* DeLupis, *supra* note
    10, at 55, 75; Roma Sadurska, *Foreign Submarines in Swedish Waters:
    The Erosion of an International Norm*, 10 [Yale J. Int'l
    L.]{.smallcaps} 34, 45-46 (1984).

[^17]: Wright, *Espionage*, *supra* note 11, at 3; Wright, *U-2
    Incidents*, *supra* note 9, at 845; *Comments of Professor Wright*,
    *in* *Panel -- The Pueblo Seizure: Facts, Law, Policy*, 63 [Proc.
    Am. Soc. Int\'l L.]{.smallcaps} 1, 28-30 (1969) \[hereinafter
    *Comments of Professor Wright*\].

[^18]: McDougal, *supra* note 10, at 394.

[^19]: The Yale "New Haven School" is associated with a "world public
    order" approach to international law. *See* Michael N. Schmitt, *New
    Haven Revisited: Law, Policy, and the Pursuit of World Order*, 1
    [A.F. Acad. J. Leg. Stud]{.smallcaps}. 185 (1990).

[^20]: McDougal, *supra* note 10, at 394. In a remarkably prophetic
    statement, the authors commented on the compulsory collection of
    information in extreme cases: \"In theory, the compulsive powers of
    the United Nations Security Council, operative upon a finding of a
    threat to the peace, could be applied to the gathering of critical
    intelligence and could, moreover, be delegated to another
    international organ . . . .\" *Id*. This describes the activity of
    the United Nations Special Commission (UNSCOM) in Iraq after the
    Gulf War of 1990.

[^21]: *Id.* at 394-95, 418-19, 444-45.

[^22]: *See* Wright, *U-2 Incidents*, *supra* note 11, at 836 (1960).
    From 1945 to 1955, the Warsaw Pact shot down nine non-military
    aircraft[.]{.smallcaps} Major Bernard E. Donahue, *Attacks on
    Foreign Civil Aircraft Trespassing in National Airspace,* 30 [A.F.
    L. Rev]{.smallcaps}. 49, 54 (1989).

[^23]: Donahue, *supra* note 22, at 62-63.

[^24]: *See* Lieutenant Commander John W. Rolph, *Freedom of Navigation
    and the Black Sea Bumping Incident: How "Innocent" Must Innocent
    Passage Be?,* [135 Mil. L. Rev]{.smallcaps}. 137 (1992).

[^25]: *See Comments of Professor Wright*, *supra* note 19, at 28-30.

[^26]: *See* Sadurska, *supra* note 16, at 34, 45-46; Delupis, *supra*
    note 10, at 67-69.

[^27]: U.N. Charter art. 51.

[^28]: U.N. Charter art. 2, para. 4.

[^29]: U.N. Charter art. 51.

[^30]: *See* 2 [Moore, Digest of International Law,]{.smallcaps} *The
    Caroline Case,* 412 (1906), *discussed in* George Bunn,
    *International Law and the Use of Force in Peacetime*, [Nav. War C.
    Rev.]{.smallcaps} 70 (May-June 1986); R.Y. Jennings, *The Caroline
    and McLeod Cases*, 32 [Am. J. Int\'l L.]{.smallcaps} 82 (1938). *See
    also* Stuart G. Baker, Note, *Comparing the 1993 U.S. Airstrike on
    Iraq to the 1986 Bombing of Libya: The New Interpretation of Article
    51*, 24 [Ga. J. Int\'l & Comp. L.]{.smallcaps} 99 (1994).

[^31]: *See* [Lieutenant Colonel Richard J. Erickson, Legitimate Use of
    Military Force Against State-Sponsored International
    Terrorism]{.smallcaps} (1989) (explaining that modern terrorism
    defies traditional international law definitions concerning use of
    force).

[^32]: *See* Gavin Cameron, *Nuclear Terrorism: A Real Threat?,* 8
    [Jane's Intel. Wkly.]{.smallcaps}, no. 9, 422 (Sept. 1, 1996).

[^33]: *See, e.g.*, Adam Treiger, *Plugging the Russian Brain Drain*, 82
    [Geo. L.J.]{.smallcaps} 237, 237-40 (1993) (discussing proliferation
    of nuclear knowledge).

[^34]: Statement of President Eisenhower, May 11, 1960, 42 [Dep't St.
    Bull.,]{.smallcaps} No. 1092, at 851-52 (May 1960).

[^35]: Statement of Secretary of State Herter, May 9, 1960, 42 [Dep't
    St. Bull.,]{.smallcaps} No. 1091, at [816-17]{.smallcaps} (May
    1960).

[^36]: *See* Bradley Graham, *Bomb Kills 23 Americans at Saudi Base,*
    [Wash. Post]{.smallcaps}, June 26, 1996, at A1.

[^37]: *See* N.R. Kleinfield, *Explosion at the Twin Towers,* N.Y.
    Times, Feb. 27, 1993, at § 1, p. 1, col. 2.

[^38]: For a good review of at the integral role intelligence plays in
    threat planning and response, see generally [Ariel Levite,
    Intelligence and Strategic Surprises]{.smallcaps} (1987).

[^39]: In an unusual case, the United Nations Security Council could
    find that a particular espionage activity threatened international
    peace and security under article 39 of the United Nations Charter.
    The Security Council then could authorize Chapter VII sanctions or
    military action to prevent it.