Flag State jurisdiction

== Definition ==
Flag State jurisdiction
Pursuant to the law of the sea, a ship has the nationality of the State whose flag it is entitled to fly.Law of the Sea Convention, Art 91(1). In turn, that State has the exclusive jurisdiction over the ship in question while the ship is on the high seas.Law of the Sea Convention, Art 92(1). See also Doris König, ‘Flag of Ships’ in Rüdiger Wolfrum (ed) Max Planck Encyclopedia of Public International Law (OUP 2008-, updated April 2009) para 25. Conversely, other States are prohibited from exercising enforcement jurisdictionEnforcement jurisdiction refers to the authority of a State to secure compliance with legal rules. Restatement (Fourth) of the Foreign Relations Law of the United States (ALI 2018) § 401. over a vessel that does not fly their flag.The Case of the S.S. “Lotus” (Judgment No. 9) (1927) PCIJ Series A No 10, “It is certainly true that – apart from certain special cases which are defined by international law – vessels on the high seas are subject to no authority except that of the State whose flag they fly… no State may exercise any kind of jurisdiction over foreign vessels upon them”; see also M/V “Norstar” judgment (Panama v Italy) (2019) 25 ITLOS (herein referred to as the M/V “Norstar” Judgment), para 216 ”…save in exceptional cases, no State may exercise jurisdiction over a foreign ship on the high seas”; Doris König, ‘Flag of Ships’ in Rüdiger Wolfrum (ed) Max Planck Encyclopedia of Public International Law (OUP 2008-, updated April 2009) para 25.
This principle of the exclusive jurisdiction of the flag State is a corollary of the rights enjoyed by vessels on the high seas – notably the freedom of navigation – as it serves to prevent interference by other States on the high seas.Y Tanaka, ‘Navigational Rights and Freedoms’ in (2015) in Donald Rothwell, Alex Oude Elfernik, Karen Scott and Tim Stephens The Oxford Handbook of the Law of the Sea (OUP 2015) 556. However, the principle is subject to specific exceptions which enable third States to exercise enforcement jurisdiction over vessels that do not fly their flag. 
One exception is provided by Article 110 of the Law of the Sea Convention,Law of the Sea Convention, Art 110 (1); the Convention makes clear that other exceptions contained in separate treaties can also exist, see for example the exceptions outlined in Convention for the Suppression of Unlawful Acts against the Safety of Maritime Navigation (entered into force 1 March 1992) 1678 UNTS 221 (SUA Convention). which grants a ‘right of visit’ to States that are not the vessel’s flag State. Under the right of visit, a State may send a designated vessel to visit and inspect a foreign private vessel.Law of the Sea Convention, Part VII, Art 110; Douglas Guilfoyle ‘The High Seas’ (2015) in Donald Rothwell, Alex Oude Elfernik, Karen Scott and Tim Stephens The Oxford Handbook of the Law of the Sea (OUP 2015) 220. The exercise of this right is dependent on there being “reasonable ground for suspecting” that the vessel is engaged in piracy,Law of the Sea Convention, Part VII, Art 110 (1) (a). slavery,Law of the Sea Convention, Part VII, Art 110 (1) (b). or unauthorised broadcasting,Law of the Sea Convention, Part VII, Art 110 (1) (c). or that the vessel is either without nationality or, in reality, of the same nationality as the inspecting State.Law of the Sea Convention, Part VII, Art 110 (1) (d-e). Whether the right of visit may be carried out using cyber means is unclear and disputed.Tallinn Manual 2.0, commentary to rule 46, para 10. 
However, the Law of the Sea Convention does not represent the totality of the legitimate exceptions to flag State jurisdiction. The ability to exercise enforcement jurisdiction over foreign vessels may also be provided for in other international treaties.Douglas Guilfoyle ‘The High Seas’ (2015) in Donald Rothwell, Alex Oude Elfernik, Karen Scott and Tim Stephens The Oxford Handbook of the Law of the Sea (OUP 2015) 219. See, e.g., the ship boarding arrangements between the US and other States as part of the Proliferation Security Initiatives, such as the Agreement between the Government of the United States of America and the Government of the Republic of Croatia concerning cooperation to suppress the proliferation of weapons of mass destruction, their delivery systems, and related materials (signed June 1 2005, entered into force 5 March 2007). Moreover, the United Nations Security Council, acting under Chapter VII of the UN Charter, may pass resolutions that compel member States to engage in enforcement actions at sea, usually with the flag State’s consent.See for example, UNSC Res 665 (14 August 1990) UN Doc S/Res/665; UNSC Res 2292 (14 June 2016) UN Doc S/Res/2292. Very few resolutions have required States to exercise their enforcement jurisdiction over foreign vessels without the flag-State’s consent.See for example, UNSC Res 665 (25th August 1990) UN Doc S/Res/665. See also Craig H Allen, “The Peacetime Right of Approach and Visit and Effective Security Council Sanctions Enforcement at Sea” (2019) 95 INT’L L. STUD 400, 406.
== Appendixes ==
=== See also ===
* Scenario 16: Cyber attacks against ships on the high seas
=== Notes and references ===
=== Bibliography and further reading ===
Category:Law of the sea
Category:Flag State jurisdiction
Category:Legal concepts