2. See the thought-provoking discussions on the websites of the American Society of International Law (www.asil.org/insights), the European Journal of International Law (www.ejil.org/forum) and Interights (www.interights.org).

3. Lawful self-defence for the purpose of protecting the security of a state and its essential interests, particular territorial integrity and political independence, should be distinguished from armed reprisals. The landmark Declaration on Principles of International Law concerning Friendly Relations and Co-operation among States in Accordance with the Charter of the United Nations, GA Res. 2625 (XXV), 24 October 1970, which is widely viewed as an authoritative interpretation of the Charter, proclaims in its Principle 1: ‘States have a duty to refrain from acts of reprisals involving the use of force.’

4. Friedlander, R.A., ‘Terrorism’, in Encyclopedia of Public International Law, Vol. IV (Amsterdam, North-Holland 2000) p. 845.Google Scholar

5. Bassiouni, M.C., International Criminal Law, Vol. 3 (Enforcement), 2nd edn. (Ardsley, NY, Transnational Publishers 1999) p. 599Google Scholar and pp. 607–608; Ferenz, B.B., An International Criminal Court- A Step Toward World Peace: A Documentary History and Analysis, Vol. 1 (New York, Oceana 1980).Google Scholar

6. See Wilson, H. A., International Law and the Use of Force of National Liberation Movements (Oxford, Clarendon 1988) pp. 130–136;Google ScholarCassese, A., Self-Determination of Peoples: A Legal Appraisal (Cambridge, Cambridge University Press 1995);Google ScholarVerwey, W.D., ‘Decolonization and the Ius ad Bellum: A Case Study on the Impact of the United Nations General Assembly on International Law’, in Akkerman, R.J. et al. , Declarations on Principles: A Quest for Universal Peace. Liber Roling (Leiden, Sijthoff 1977) pp. 121–140.Google Scholar

7. Bassiouni, M.C., ‘International Terrorism’, in his (ed.) International Criminal Law, Vol. 1 (Crimes), 2nd edn. (Ardsley, NY, Transnational Publishers 1999) pp. 795–796.Google Scholar

8. See also Gilbert, G., ‘The “law” and “transnational terrorism”’, 26 NYIL (1995) pp. 3–32.CrossRefGoogle Scholar

9. See for a review Boutros-Ghali, B., ‘The United Nations and Comprehensive Legal Measures for Combating International Terrorism’, in Wellens, K.C., ed., International Law: Theory and Practice (The Hague, Nijhoff 1998) pp. 287–304;Google ScholarHiggins, R. and Flory, M., eds., Terrorism and International Law (London, Routledge 1997). See also the annual reports by the UN Secretary-General on the status of ratification records of anti-terrorism conventions.CrossRefGoogle Scholar

10. Convention of Offences and Certain Other Acts Committed on Board Aircraft, Tokyo, 14 September 1963, 704 UNTS p. 219,Google Scholar entry into force 4 December 1969, 172 parties; Convention for the Suppression of Unlawful Seizure of Aircraft, The Hague, 16 December 1970, 860 UNTS p. 105,Google Scholar entry into force 14 October 1971, 174 parties; Convention for the Suppression of Unlawful Acts against the Safety of Civil Aviation, Montreal, 23 September 1971, 10 ILM (1971) p. 1151, entry into force 26 anuary 1973, 175 parties, and its Protocol on the Suppression of Unlawful Acts of Violence at Airports Serving International Civil Aviation, Montreal, 24 February 1988, ICAO Doc. 9518, entry into force 6 August 1989, 107 parties; Convention on the Marking of Plastic Explosives for the Purpose of Detection, Montreal, 1 March 1991, UN Doc. S/22393, Annex, entry into force 21 June 1998, 69 parties; Convention for the Suppression of Unlawful Acts against the Safety of Maritime Navigation, Rome, 10 March 1988, doc. SUA/CONF/15/Rev. 1, entry into force 1 March 1992, 56 parties, and its Protocol for the Suppression of Unlawful Acts against the Safety of Fixed Platforms Located on the Continental Shelf, Rome, 10 March 1988, doc. SUA/CONF/16/Rev. 2, 1 March 1992, 51 parties.Google Scholar

11. Convention on the Prevention and Punishment of Crimes against Internationally Protected Persons including Diplomatic Agents, New York, 14 December 1973, 1035 UNTS p. 167 and 13 ILM (1974) p. 41, entry into force 20 February 1977, 107 parties.Google Scholar

12. International Convention against the Taking of Hostages, New York, 17 December 1979, 1316 UNTS p. 205 and 18 ILM (1979) p. 1457, entry into force 3 June 1983, 97 parties.Google Scholar

13. Convention on the Physical Protection of Nuclear Material, Vienna, 3 March 1980, 1456 UNTS no. 24631, entry into force 8 February 1987, 69 parties; International Convention for the Suppression of Terrorist Bombings, New York, 15 December 1997, UN Doc. A/RES/52/164, Annex, entry into force 23 May 2001, 29 parties.Google Scholar

14. International Convention for the Suppression of the Financing of Terrorism, New York, 9 December 1999, UN Doc. A/RES/54/109, Annex, not yet in force, 5 parties.Google Scholar

15. OAS Convention to Prevent and Punish Acts of Terrorism Taking the Form of Crimes against Persons and Related Extortion that are of International Significance, Washington, 2 February 1971, OAS Treaty Series, no. 37 and 10 ILM (1971) p. 255, entry into force in 1976, 13 parties.Google Scholar

16. European Convention on the Suppression of Terrorism, Strasbourg, 27 January 1977, ETS, no. 90, entry into force 4 August 1978, 36 parties.

17. SAARC (South Asian Association for Regional Co-operation) Regional Convention on the Suppression of Terrorism, Kathmandu, 4 November 1987.

18. Arab Convention on the Suppression of Terrorism, Cairo, 22 April 1998.

19. Treaty on Co-operation among States Members of the Commonwealth of Independent States in Combating Terrorism, Minsk, 4 June 1999.

20. Convention of the Organization of the Islamic Conference on Combating International Terrorism, Ouagadougou, 1 July 1999.

21. OAU Convention on the Prevention and Combating of Terrorism, Algiers, 14 July 1999.

22. For example, the bombing of the PLO Headquarters near Tunis, Tunisia, 1985, by Israeli forces. This was vigorously rejected by the UN Security Council by 14–0 in S/RES/573 (1985).

23. For example, the bombing raid on Libya in April 1986 in response to death and injury among American service men after a bomb explosion in a Berlin discotheque and against ‘the terrorist infrastructure of the Iraqi regime’ in 1993 following an allegedly planned but not executed assassination attempt of former President Bush on a visit in Kuwait in April 1993.

24. Incursions by the South African army from Namibia into Angola and Zambia allegedly to stop terrorism.

25. For example, in the Nicaragua case the Court stated that the exercise of the right of self-defence by a state under Art. 51 ‘is subject to the State concerned having been the victim of an armed attack’. Military and Paramilitary Activities (Nicaragua v. United States), ICJ Reports (1986) p. 103, para. 195.

26. See Arts. 100–107 of the 1982 UN Convention on the Law of the Sea, entry in force 16 November 1994. Text in 21 ILM (1982) p. 1261.Google Scholar

27. The World Conference on Human Rights reaffirmed that terrorism is indeed aimed at the destruction of human rights, fundamental freedoms and democracy, in Vienna Declaration and Programme of Action, 25 June 1993, UN Conf. A/CONF. 157/24 (part I), chapter III. See also A/RES/54/164, 17 December 1999, on Human Rights and terrorism and the reports by the UN Secretary-General in UN Docs. A/54/439 (1999) and A/56/190 (2001).

28. See Art. l(f) of the UN Convention relating to the Status of Refugees, 25 July 1951; van Krieken, P.J., ed., Refugee Law in Context: The Exclusion Clause (The Hague, T.M.C. Asser Press 1999).CrossRefGoogle Scholar

29. Declaration on Principles of International Law concerning Friendly Relations and Co-operation among States in Accordance with the Charter of the United Nations, GA Res. 2625 (XXV), 24 October 1970, Principle 1 on the prohibition of the threat or use of force. See also the preceding sentence: ‘Every State has the duty to refrain from organizing or encouraging the organization of irregular forces or armed bands, including mercenaries, for incursion into the territory of another State.’ Furthermore, Principle 3 stipulates: ‘… no State shall organize, assist, foment, finance, incite or tolerate subversive, terrorist or armed activities directed towards the violent overthrown of the regime in another State, or interfere in civil strife in another State.’

30. GA Res. 3314 (XXIX), Annex, 14 December 1974, para. 3(g). Emphasis added.

31. A/RES/49/60, Annex, 9 December 1994, para. 3.

32. Most recently, A/RES/55/158, 12 December 2000.

33. A/RES/51/210, Annex, 17 December 1996.

34. See UN Doc. S/23500, 31 January 1992. Text in 31 INM (1992) p. 758.Google Scholar

35. See also the non-committtal statement by the President of the Security Council of 6 December 2000, UN Doc. S/PRST/2000/38.

36. See also Marauha, T., ‘Terrorism: addendum 1999’, in Bernhardt, R., Encyclopedia of Public International Law, Vol. IV (Amsterdam, North-Holland 2000) pp. 849–858 at pp. 850–852.Google Scholar

37. See S/RES/579 (1985) and S/RES/638 (1989) concerning hostage-taking and abduction in Lebanon.

38. S/RES/731 and 748 (1992), 883 (1993) and 1192 (1998).

39. S/RES/1044 (1996).

40. S/RES/1189 (1998). For different views on the subsequent missile strikes against Afghanistan and Sudan, see Lobel, J., ‘The Use of Force to Respond to Terrorist Attacks: The Bombing of Sudan and Afghanistan’, 24 Yale JIL (1999) pp. 537–557Google Scholar; R. Wedgwood, ‘Responding to Terrorism: The Strikes against bin Laden’, ibid., pp. 559–576.

41. S/RES/1076 (1996).

42. S/RES/1214 (1998).

43. S/RES/1267 (1999).

44. See the Report of the UN Security Council 2000–2001, UN Doc. A/56/2, p. 275. See on the role of sanctions committees Schrijver, N. J., ‘The Use of Economic Sanctions by the UN Security Council: An International Law Perspective’, in Post, H.H.G., ed., International Economic Law and Armed Conflict (Dordrecht, Nijhoff) pp. 123–161 at pp. 151–152 and 157–158.Google Scholar

45. See on the energetic start of the Counter-Terrorism Committee led by the British Permanent Representative UN Doc. S/2001/935 and http://www.un.org/docs/sc/committees/1373.

46. See the Report of the Working Group in UN Doc. A/C.6/56/L.9, 29 October 2001.

47. Art. 2, paras. 3 and 4 of the Charter of the United Nations.

48. See, for example, Brownlie, I., Principles of Public International Law, 5th edn. (Oxford, Oxford University Press 1998) p. 515;Google ScholarCassese, A., International Law (Oxford, Oxford University Press 2001) p. 236;Google ScholarRoling, B.V.A., ‘Aspects of the Ban on Force’, 24 NILR (1977) pp. 242–259;CrossRefGoogle ScholarSchachter, O., International Law in Theory and Practice (Dordrecht, Nijhoff 1991) p. 131.Google Scholar

49. Cf, Arts. 53 and 64 of the 1969 Vienna Convention on the Law of Treaties, 23 May 1969, in force 27 January 1980. Text in 1155 UNTS p. 331 and 8 ILM (1969) p. 679.Google Scholar

50. Military and Paramilitary Activities (Nicaragua v. Unites States), ICJ Reports (1986) p. 100, para. 190.

51. See also the excellent commentaries by Cassese, A., ‘Article 51’, in J-P Cot and Pellet, A., La Charte des Nations Unies. Commentaire article par article, 2nd edn. (Paris, Economica 1991) pp. 771–795Google Scholar and Randelzhofer, A., ‘Article 51’, in Simma, B., et al. , eds., The Charter of the United Nations: A Commentary (Oxford, Oxford University Press 1994) pp. 661–678.Google Scholar

52. For a succinct review of this issue see Gill, T.D., ‘Legal and Some Political Limitations on the Power of the UN Security Council to Exercise Its Enforcement Powers under Chapter VII of the Charter’, 26 NYIL (1995) pp. 33–138 at pp. 90–106;CrossRefGoogle ScholarDinstein, Y., War, Aggression and Self-Defence, 3rd edn. (Cambridge, Cambridge University Press 2001) pp. 187–189.CrossRefGoogle Scholar

53. Schrijver, N.J., ‘The United Nations and the Use of Force: Comparing the Korea and the Gulf Crises from a Legal Perspective’, in Krieken, P.J. van and Pannenborg, Ch. O., eds., Liber Akkerman: In- and Outlaws in War (Apeldoorn, Maklu publishers 1992) pp. 255–266. For a different view see Gill, op. cit. n. 52, at p. 99.Google Scholar

54. NATO Press release 2001, no. 124. Full text on website NATO: www.nato.int/terrorism.

55. Art. 5 of the North Atlantic Treaty Organization (‘Treaty of Washington’, 4 April 1949, text in 34 UNTS p. 243) reads: ‘The Parties agree that an armed attack against one or members in Europe or North America shall be considered an attack against them all; and consequently they agree that, if such an armed attack occurs, each of them, in the exercise of the right to individual or collective selfdefence recognised by Article 51 of the Charter of the United Nations, will assist the Party or Parties so attacked by taking forthwith, individually and in concert with other Parties, such action as it deems necessary, including the use of armed force, to restore and maintain the security of the North Atlantic area.

Any such armed attack and all measures taken as a result thereof, shall immediately be reported to the Security Council. Such measures shall be terminated when the Security Council has taken the measures necessary to maintain or restore international peace and security.’

56. See also Ignarski, J.S., ‘NATO’, in Bernhardt, R., ed, Encyclopedia of Public International Law, Vol. III (Amsterdam, North-Holland 1997) p. 651.Google Scholar This differs from the obligation of collective selfdefence as set out in Art. V of the Brussels Treaty of 1948 establishing the Western European Union. Text in 19 UNTS p. 51.

57. See UN Docs. S/2001/946 and S/2001/947, 7 October 2001.

58. See also Art. 7 of the NATO Treaty, reading: “This Treaty does not affect, and shall not be interpreted as affecting in any way the rights and obligations under the Charter of the Parties which are members of the United Nations, or the primary responsibility of the Security Council for the maintenance of peace and security.’ See also Simma, B., ‘NATO, the UN and the Use of Force: Legal Aspects’, 10 EJIL (1999) pp. 1–22 andCrossRefGoogle ScholarBlokker, N.M., ‘Is the Authorization Authorized? Powers and Practice of the UN Security Council to Authorize the Use of Force by “Coalitions of the Able and Willing’”, 11 EJIL (2000) pp. 541–568.CrossRefGoogle Scholar

59. See Meng, W., ‘The Caroline’, in R., Bernhardt, ed., Encyclopedia of Public International Law, Vol. I (Amsterdam, North-Holland 1992) pp. 537–538. Letter ofGoogle ScholarMrWebster, in Dixon, M. and McCorquodale, R., Cases & Materials on International Law, 3rd edn. (London, Blackstone 2000) p. 562.Google Scholar

60. Legality of the Threat or Use of Nuclear Weapons, Advisory Opinion, ICJ Reports (1996) p. 257, para. 78.

61. Moreover, it is notable that the Council refers to ‘steps’ rather than to the more usual word ‘measures’. In the author’s view ‘steps’ have a more procedural connotation, while ‘measures’ denote concrete action to be taken. Art. 51 of the UN Charter uses the word ‘measures’.

62. Like in Resolution 1368 (2001), this paragraph is included in the preamble. Its formulation is somewhat curiously: ‘Reaffirming the inherent right of individual or collective self-defence as recognized by the Charter of the United Nations as reiterated in resolution 1368 (2001).’

63. See supra nn. 29 and 30, respectively.

64. See supra n. 49.

65. Fassbender, B., ‘The United Nations Charter as a Constitution of the International Community’, 36 Columbia Journal of Transnational Law (1998) pp. 529–619 and hisGoogle ScholarUN Security Council Reform and the Right of Veto: A Constitutional Perspective (The Hague, Kluwer 1998) pp. 130–131.Google Scholar

66. See on the issue of attribution Art. 8 of the Draft Articles on Responsibility of States for Internationally Wrongful Acts and Commentary, as adopted by the ILC in August 2001, UN Doc. A/56/10, 2001, pp. 103–109. Draft Art. 8 reads: ‘The conduct of a person or group of persons shall be considered an act of a State under international law if the person or group of persons is in fact acting on the instructions of, or under the direction or control of, that State in carrying out the conduct.’

67. Military and Paramilitary Activities (Nicaragua v. Unites Stales), ICJ Reports (1986) pp. 50–54, paras. 86–93.

See on varying levels of state support the excellent articles by Cassese, A., ‘The International Community’s “Legal” Response to Terrorism’, 38 ICLQ (1989) pp. 589–608 at pp. 598–600, andCrossRefGoogle ScholarTravalio, G.M., ‘Terrorism, International Law, and the Use of Force’, 18 Wisconsin ILJ (2000) pp. 145–191 at pp. 150–151.Google Scholar

68. Paramilitary and Military Activities (Nicaragua v. United States), ICJ Reports (1986) p. 62, para. 109, pp. 63–64, paras. 113–115 and pp. 103–104, para. 195.

69. Ibidem, p. 62, para. 108 and p. 65, para. 116.

70. Diplomatic and Consular Staff at Tehran (United States v. Iran), ICJ Reports (1980) p. 36, para. 74.

71. ICTY, Prosecutors v. Tadic, Case IT-94–1, Appeals Chamber, 1999, published in 38 ILM (1999) p. 1518 at p. 1546, para. 145.

72. See the letter dated 7 October 2001 from the US to the Security Council, UN Doc. S/2001/946, stating: ‘There is still much we do not know. Our inquiry is in its early stages. We may find that our self-defence requires further actions with respect to other organizations and other States’ (emphasis added). During a press conference Ambassador Negopronte further remarked on this sentence: ‘… when you’re talking about the inherent right of self-defence, I don’t think that one would want to limit oneself in any particular way. I think one exercises it, when one thinks that is justified and necessary.’ Text in USUN Press Release 136 (01), 8 October 2001. Such pronouncements cannot be found in the UK letter to the Security Council of 7 October 2001 (UN Doc. S/2001/947) invoking the right of self-defence following the initiation of military action on that day.

73. Detter, I., The Law of War, 2nd edn. (Cambridge, Cambridge University Press 2000) p. 153 and p. 303;Google ScholarKalshoven, F. and Zegveld, L., Constraints on the Waging of War: An Introduction to International Humanitarian Law, 3rd edn. (Geneva, ICRC 2001) pp. 19–21.Google Scholar

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75. On the evolution of this concept, see Bassiouni, M.C., Crimes against Humanity in International Criminal Law, 2nd edn. (The Hague, Kluwer 1999);Google ScholarRobertson, G., Crimes against Humanity: The Struggle for Global Justice (London, Allan Lane 1999);Google ScholarFerenz, B.B., ‘Crime Against Humanity’, in Bemhardt, R., ed., Encyclopedia of Public International Law, Vol. I (Amsterdam, North-Holland 1992) p. 870.Google Scholar

76. See Art. 6(c) of the 1945 Charter of the International Military Tribunal, Annexed to the London Agreement of 8 August 1945 for the Prosecution and Punishment of Major War Criminals of the European Axis, 1945, text in 82 UNTS p. 279.

77. The only difference is that religious grounds are not referred to but only ‘persecutions on political or racial grounds’. See Art. 5(c) of the Charter of the International Military Tribunal for the Far East, 1946.

78. Art. 5 of the Statute of the International Criminal Tribunal for the Former Yugoslavia, approved by the Security Council in S/RES/827 (1993). Text in 32 ILM (1993) p. 1192.

79. Art. 3 of the Statute of the International Criminal Tribunal for Rwanda, approved by the Security Council in S/RES/955 (1994). Text in 33 ILM (1994) p. 1601.

80. See Art. 7 of the Rome Statute of the International Criminal Court, 1998. Text in 37 ILM (1999) pp. 1004–1005.

81. See the rich case note by Dinstein, Y., ‘Crimes against Humanity after Tadic’, 13 LJIL (2000) pp. 373–393 at pp. 386–387.CrossRefGoogle Scholar

82. See van Ginkel, B.T., ‘Terrorisme in internationaal juridisch perspectief, 29 Vrede en Veiligheid [Peace and Security – Dutch Journal of Peace Research] (2000) pp. 393–412 at p. 396.Google Scholar

83. See UN Doc. A/CONF.183/C.1/L.27, referred to by A. Cassese, ‘Terrorism is Also Disrupting Some Crucial Legal Categories of International Law’, EJIL Forum, www.ejil.org, October 2001. See also Robinson, D., ‘Defining “Crimes against Humanity” at the Rome Conference’, 93 AJIL (2000) pp. 43–56.CrossRefGoogle Scholar

84. See Sailer, T.M., ‘The International Criminal Court: An Argument to Extend Its Jurisdiction to Terrorism and a Dismissal of U.S. Objections’, 13 Temple International and Comparative Law Journal (1999) pp. 311–346.Google Scholar

85. Resolution E adopted by the UN Diplomatic Conference of Plenipotentiaries on the Establishment of an International Criminal Court, 17 July 1998.

86. Press releases at www.un.org of 18 October 2001.

87. The main concern of the United States is that its soldiers in peace-keeping operations could be brought before the Court by a third state on the territory of which alleged crimes of international concern concurred. Cf, Art. 12, para. 2(a) of the Rome Statute of the International Criminal Court.

88. Cf., Gilbert, G., ‘Crimes sans frontieres: Jurisdictional Problems in English Law’, 63 BYIL (1992) pp. 415–442.Google Scholar

89. ICJ Reports (1986) p. 94, para. 176, as quoted by Cassese, A., International Law (Oxford, Oxford University Press 2001) p. 305.Google Scholar

90. See Arts. 24, 39 and 51 of the UN Charter. The primary responsibility of the Security Council is also recognised in Arts. 1 and 7 of the NATO Treaty.

91. This rule of non-retroactivity ratione personae is included in Art. 24, para.l of the Rome Statute, reading: ‘No person shall be criminally responsible under this Statute for conduct prior to the entry into force of the Statute.’

92. See also on this long-term approach Security Council Resolution 1377 of 12 November 2001, as quoted at p. 279 supra and Cassese, loc. cit. n. 67.