¹ The participants, who came from many countries, were both specialists in international law and naval experts, the latter including operational and nonoperational personnel. About one-third of the participants were academic personnel and the others were government officials. All the participants attended in their personal capacity.

² The meetings were convened by the San Remo International Institute of Humanitarian Law. The undersigned acted as coordinator of the drafting work and general editor.

³ The first meeting, in 1987, was co-organized by the University of Pisa, Syracuse University (New York) and the San Remo Institute. A full report of the first meeting is reproduced in 14 Syracuse J. Int’l L. & Com. 553 (1988) (special issue).

⁴ The decision to work on a manual was made at the second meeting, in 1988.

⁵ In 1990 the participants decided to work on a commentary (now called the “Explanation”) to appear at the same time as the Manual. See The San Remo Manual on International Law Applicable to Armed Conflicts at Sea (Louise Doswald-Beck ed., forthcoming 1995) [hereinafter Explanation and Manual, respectively].

⁶ Hague Conventions [No. VI] Relating to Status of Enemy Merchant Ships at the Outbreak of Hostilities, 205 Consol. TS 305; [No. VII] Relating to the Conversion of Merchant-ships into Warships, id. at 319; [No. VIII] Relating to the Laying of Automatic Submarine Contact Mines, id. at 331, 36 Stat. 2332; [No. IX] Respecting Bombardment by Naval Forces in Time of War, 205 Consol. TS 345, 36 Stat. 2351; [No. XI] Relating to Certain Restrictions on the Right of Capture in Maritime War, 205 Consol. TS 367, 36 Stat. 2396; and [No. XIII] Respecting the Rights and Duties of Neutral Powers in Maritime War, 205 Consol. TS 395, 36 Stat. 2415. All the Conventions were signed Oct. 18, 1907; the texts in Consol. TS are in French. See also London Proces-Verbal Relating to the Rules of Submarine Warfare, Nov. 6, 1936, 173 LNTS 353, 3 Bevans 298 (generally considered to be a treaty that is technically in force but of doubtful effectiveness).

⁷ Office of the Chief of Naval Operations, U.S. Dep’t of the Navy, Naval Warfare Pub. No. NWP 9 (Rev. A)/FMFM 1–10, The Commander’s Handbook on the Law of Naval Operations (1987), reprinted in U.S. Naval War College, International Law Studies No. 64, The Law of Naval Operations 385 (1991) [hereinafter U.S. Handbook]. See also Office of the Judge Advocate General, U.S. Dep’t of the Navy, Annotated Supplement to the Commander’s Handbook on the Law of Naval Operations (1989).

⁸ Other contemporary manuals with a section on the law applicable to armed conflict at sea are the German triservice manual, Federal Ministry of Defence, No. ZDv 15/2, Humanitarian Law in Armed Conflicts (1992); and Canadian Forces Law of Armed Conflict Manual (2d draft n.d.). The participants in the project that led to the San Remo Manual felt that a manual needed to be developed that reflected the views of experts from different parts of the world and that national manuals could not be relied on alone, especially as there are so few contemporary ones, to assess a representative view of the law.

For the London Declaration concerning the Laws of Naval War, Feb. 26, 1909, see The Laws of Armed Conflicts 845 (Dietrich Schindler & Jifi Toman eds., 3d rev. ed. 1988). For the Laws of Naval War Governing the Relations between Belligerents, Manual adopted by the Institute of International Law [Oxford Manual of Naval War], Aug. 9, 1913, see id. at 857.

⁹ For an indication of the traditional customary law, i.e., pre-1914, see, in particular, Final Protocol of the London Naval Conference and Declaration concerning the Laws of Naval War, Feb. 26, 1909, 7 Martens Nouveau Recueil (ser. 3) 39, reprinted in The Laws of Armed Conflicts, supra note 8, at 843 [hereinafter Final Protocol and Declaration]; and 2 Oppenheim, infra note 20, War and Neutrality 225–37 (2d ed. 1912). For a detailed description and analysis of the law, see Wolff Heintschel von Heinegg, Visit, Search, Diversion and Capture in Naval Warfare, 29 Can. Y.B. Int’l L. 283 (1991). This article is a revised version of the Introductory Report on the same subject, infra note 12.

¹⁰ Protocol Additional to the Geneva Conventions of 12 August 1949, and Relating to the Protection of Victims of International Armed Conflicts, opened for signature Dec. 12, 1977, 1125 UNTS 3 [hereinafter Protocol I]. See U.S. Handbook, supra note 7, para. 8.1.1; German Manual, supra note 8, paras. 442, 1017.

¹¹ For example, the Manual incorporates recommendations of the International Civil Aviation Organization (ICAO) on the safety of civil aircraft and procedures for interception, but it also allows attack in certain well-defined situations. Another example is the attempt, in the section on “zones,” to allow certain navigational rights as far as possible in exclusion zones declared by belligerents. These subjects will be elaborated on below.

¹² The Introductory Reports, special papers and participants' written comments are published in the original English in Bochumer Schriften zur Friedensicherung und zum Völkerrecht (Wolff Heintschel von Heinegg ed., 1991). The Introductory Reports were as follows: Coram. William J. Fenrick, The Military Objective and the Principle of Distinction in the Law of Naval Warfare; Gert-Jan F. Van Hegelsom, Methods and Means of Combat in Naval Warfare; Prof. Wolff Heintschel von Heinegg, Visit, Search, Diversion and Capture; Christopher Greenwood, The Effect of the United Nations Charter on the Law of Naval Warfare; Prof. Horace Robertson (R. Adm., U.S. Navy, ret.), Regions of Operations of Naval Warfare—Different Maritime Areas; Louise Doswald-Beck, Protection of Victims of Armed Conflicts at Sea. A special report on the law applicable to aircraft during naval operations was prepared by Vice-Adm. James Doyle (U.S. Navy, ret.). Special papers on neutrality and nonbelligerency were prepared by Prof. Dietrich Schindler and Prof. Heintschel von Heinegg, and on the protection of the environment during armed conflict by Prof. Salah El-Din Amer and Lt. Col. Kim Carter. Finally, a special paper on the use of the terms “respect” and “due regard” was prepared by Capt. J. Ashley Roach.

¹³ See Geneva Convention [No. II] for the Amelioration of the Condition of Wounded, Sick and Shipwrecked Members of Armed Forces at Sea, Aug. 12, 1949, Art. 34, 6 UST 3217, 75 UNTS 85.

¹⁴ Annex I was amended pursuant to Article 98 of Additional Protocol I and came into force in March 1994. See Protocol Additional to the Geneva Conventions of 12 August 1949, Annex I, Regulations Concerning Identification, Int’l Rev. Red Cross, Jan.–Feb. 1994, at 29. The Manual and its Explanation take this new development into account.

¹⁵ It should be noted that, for the purposes of the Manual, the term “international humanitarian law” is defined broadly to include not only so-called Geneva law on the protection of victims of war, but also so-called Hague law on the rules regulating the conduct of hostilities. The term also includes, for the purposes of the Manual, rules on the rights and duties of neutrals insofar as they relate to conduct at sea and the treatment of captured persons, but not those on the adjudication of prizes. See Manual, supra note 5, para. 13(a); Explanation, supra note 5, paras. 13.1–13.4.

¹⁶ Manual, supra note 5, paras. 7–9. In particular, it is specified that if the Security Council is taking measures under chapter VII, UN member states may not rely on the law of neutrality to justify conduct that is incompatible with these measures.

¹⁷ See Explanation, supra note 5, paras. 13.11–13.14 (commenting on para. 13(d) of the Manual).

¹⁸ See, in particular, Constantine John Colombos, International Law of the Sea §791 & n.5, §792 n.1 (6th ed. 1967).

¹⁹ Final Protocol and Declaration, supra note 9, Art. 49.

²⁰ Merchant vessels were frequently sunk in the First and Second World Wars. See, e.g., Robert W. Tucker, The Law of War and Neutrality at Sea 57–67 (U.S. Naval War College, International Law Studies No. 40, 1955); 2 Lassa Oppenheim, International Law: A Treatise: Disputes, War and Neutrality 487–93, §194 a–b (Hersch Lauterpacht ed., 7th ed. 1952).

²¹ This was reaffirmed in the Nuremberg judgment against Admirals Donitz and Raeder, see International Military Tribunal (Nuremberg), Judgment and Sentences, 41 AJIL 172, 302–09 (1947), which stated that, if the commander of a submarine is unable, for the safety of his vessel, to conform to the rules, he must allow the merchant vessel to pass safely. In the circumstances, this ruling related only to neutral shipping because the Tribunal took into account the fact that the Allies had ordered their merchant ships to give information on sightings of German submarines and to ram them if possible. It was clear, however, that the judgment was meant to reaffirm the validity of the 1936 treaty, supra note 6, in general.

²² See especially U.S. Handbook, supra note 7, para. 8.2.2.2; and German Manual, supra note 8, paras. 1025, 1026. Both of these manuals repeat the rules of the 1936 Proces-Verbal, supra note 6, but only as being applicable in relation to vessels that are not military objectives. Those which are military objectives, as denned in the same paragraphs of these manuals, may be attacked on sight.

²³ See especially New Rules for Victims of Armed Conflicts 274–86, 293–327 (Michael Bothe, Karl Josef Partsch & Waldemar A. Solf eds., 1982) (commenting on Protocol I and explaining this development). For a description of the development of the principle of distinction in customary law since its lapse in the Second World War and its reaffirmation in the Additional Protocols of 1977, see Louise Doswald-Beck, The Value of the 1977 Geneva Protocols for the Protection of Civilians, in Armed Conflict and the New Law 137 (Michael A. Meyer ed., 1989).

²⁴ There are 135 states that are now party to this treaty.

²⁵ For a description of aerial attacks during the Second World War and the justifications given at that time, see, e.g., David Johnson, Rights in Air Space 44–55 (1965).

²⁶ See especially James M. Spaight, Air Power and War Rights 271–80 (3d ed. 1947).

²⁷ See, for a critical description of this doctrine, Frits Kalshoven, The Law of Warfare 38–39 (1973).

On the term “war-fighting/war-sustaining effort,” see Explanation, supra note 5, para. 60.11; Frits Kalshoven, Noncombatant Persons: A Comment to Chapter 11 of the Commander’s Handbook on the Law of Naval Operations, in The Law of Naval Operations, supra note 7, at 300, 310 (stating, “To add ‘war-sustaining effort’ is going too far … as this might easily be interpreted to encompass virtually every activity in the enemy country.”).

²⁸ See especially William J. Fenrick, Legal Aspects of Targeting in the Law of Naval Warfare, 29 Can. Y.B. Int’l L. 238, 255–63 (1991). This article is a revised version of the Introductory Report, supra note 12.

²⁹ See id. at 259–61.

³⁰ Part of the definition of the military objective found in Protocol I, supra note 10, Art. 52(2), and repeated in Manual, supra note 5, para. 40.

³¹ See International Military Tribunal, supra note 21.

³² This view was put forward in Fenrick, supra note 12.

³³ U.S. Handbook, supra note 7, para. 7.4. Examples given in the annotation to this paragraph are “imports of raw materials used for the production of armaments and exports of products the proceeds of which are used by the belligerent to purchase arms and armaments.” Id. at 7-23 n.90.

³⁴ Manual, supra note 5, paras. 98, 146(f).

³⁵ Id., para. 47. For a description of the legal bases for these exemptions, see the Explanation to this paragraph, supra note 5; and for more detail, including possible means of identifying these vessels, see Doswald-Beck, supra note 12.

⁵⁶ See, e.g., U.S. Handbook, supra note 7, para. 8.2.3, subpara. 6, at 8-20; German Manual, supra note 8, para. 1034.

³⁷ Although not exclusively, as some innovations are introduced, such as a reference to navicerts and a prohibition of the destruction of passenger vessels at sea, even after capture, unless the passengers are first disembarked at a port.

³⁸ Manual, supra note 5, paras. 119, 121. There are similar provisions for the diversion of aircraft at paras. 125, 126.

³⁹ However, a restriction on traditional law was introduced in order to prohibit the destruction at sea of passenger vessels carrying civilian passengers. The Manual states that such captured vessels must first be brought to port so as to disembark the passengers on land safely, before resorting to destruction of the vessel. Id., paras. 140, 152. If, therefore, a belligerent is unable to follow this procedure, he must abstain from destroying the vessel or let the vessel proceed. The possibility of destroying other merchant vessels at sea after off-loading passengers and crew was retained because far fewer persons would be involved. Such destruction after capture is not to be confused with attack, which is not allowed unless the vessel is a military objective. Further, off-loading passengers after capture and prior to destruction is not to be confused with the duty to try to rescue the shipwrecked after an attack, which is provided for in Article 18 of the second Geneva Convention, supra note 13.

⁴⁰ The participants decided to avoid the use of this term, as it gives the impression that belligerents may totally prohibit the use of certain areas. Other possible terms were discussed such as “operations zones” or “maritime operations zones” (suggested by the Rapporteur on Methods and Means of Combat in Naval Warfare). After much debate in the drafting group, where various suggestions were rejected, the simple term “zone” was retained.

⁴¹ For a description and analysis of the use of such zones, see, in particular, William J. Fenrick, The Exclusion Zone Device in the Law of Naval Warfare, 24 Can. Y.B. Int’l L. 91 (1986). See also G. P. Politakis, Waging War at Sea: The Legality of War Zones, 38 Neth. Int’l L. Rev. 125 (1991).

⁴² Manual, supra note 5, para. 34. Paragraph 35 gives further specifications with regard to the possible mining of such zones, in particular notification of the neutral state.

⁴⁹ Id., para. 22.

⁴⁴ Nov. 23, 1972, 27 UST 37. See Explanation, supra note 5, paras. 11.1–11.7.

⁴⁵ Manual, supra note 5, para. 44.

⁴⁶ Drafted Dec. 1922–Feb. 1923, reprinted in The Law of Armed Conflicts, supra note 8, at 207, 17 AJIL 245 (Supp. 1923) [hereinafter Hague Rules]. It is generally accepted that the draft rules of 1923 reflected customary rules of that time, but that not all of their provisions can be considered a valid reflection of contemporary law, in particular, those on aerial bombardment in Article 24, paragraphs 2–4.

⁴⁷ Convention on International Civil Aviation, Dec. 7, 1944, 61 Stat. 1180, 15 UNTS 295.

⁴⁸ Manual, supra note 5, para. 53.

⁴⁹ Id., para. 13(m).

⁵⁰ Hague Rules, supra note 46, Art. 17; Hague Convention [No. X] for the Adaptation of the Principles of the Geneva Convention to Maritime War, Oct. 18, 1907, 36 Stat. 2351, 205 Consol. TS 359 (French).

⁵¹ I.e., are not innocently employed in their normal role, intentionally hamper the movements of combatants, and, in the case of aircraft exempt from attack as a result of a safe-conduct, do not comply with the details of the agreement. Manual, supra note 5, paras. 55, 56. Paragraph 54 of the Manual specifies that medical aircraft are exempt from attack only if they are recognized as such, or are acting in compliance with an agreement, or are flying in areas under the control of their own or friendly forces or outside the area of armed conflict (these conditions are a summary of the rules found on this point in Protocol I, supra note 10).

⁵² Manual, supra note 5, para. 57. These conditions, mutatis mutandis, are also indicated for the case of protected vessels that have breached their condition of protection. Id., para. 52.

⁵⁵ Id., para. 63. The other activities include engaging in acts of war on behalf of the enemy (examples are given, such as laying mines and engaging in electronic warfare); acting as an auxiliary aircraft to an enemy’s armed forces; incorporation into or assisting the enemy’s intelligence-gathering system; flying under the protection of accompanying enemy warships or military aircraft; being armed with air-to-air or air-to-surface weapons and undertaking certain maneuvers (such as refusing an order to identify itself).

⁵⁴ The actions that may render a civil aircraft liable to attack are that the aircraft concerned

(a) are believed on reasonable grounds to be carrying contraband, and, after prior warning or interception, they intentionally and clearly refuse to divert from their destination, or intentionally and clearly refuse to proceed for visit and search to a belligerent airfield that is safe for the type of aircraft involved and reasonably accessible;

(b) engage in belligerent acts on behalf of the enemy;

(c) act as auxiliaries to the enemy’s armed forces;

(d) are incorporated into or assist the enemy’s intelligence system, or

(e) otherwise make an effective contribution to the enemy’s military action ….

Id., para. 70.

⁵⁶ Id., subpara. (e).

⁵⁶ Manual, supra note 5, para. 46. These reflect the precautions applicable to an intended attack in the case of armed conflict on land.

⁵⁷ ICAO Doc. 9554–AN/932 (1990).

⁵⁸ Manual, supra note 5, paras. 72–77. A detailed analysis of the problems of identification is contained in Doswald-Beck, supra note 12.

⁵⁹ Paragraph 1, which defines the scope of application of the law, refers simply to the “parties to an armed conflict at sea.”

⁶⁰ It has already influenced some developments; for example, the pertinent sections of the new German Manual, supra note 8, were influenced by this process.