Published online by Cambridge University Press: 20 January 2017
There has been an ongoing debate over recent years about the scope of a state’s right of selfdefense against an imminent or actual armed attack by nonstate actors. The debate predates the Al Qaeda attacks against the World Trade Center and elsewhere in the United States on September 11,2001, but those events sharpened its focus and gave it greater operational urgency. While an important strand of the debate has taken place in academic journals and public forums, there has been another strand, largely away from the public gaze, within governments and between them, about what the appropriate principles are, and ought to be, in respect of such conduct. Insofar as these discussions have informed the practice of states and their appreciations of legality, they carry particular weight, being material both to the crystallization and development of customary international law and to the interpretation of treaties.
1 For a public statement of the position as it came to be in the second term of the Bush administration, see the remarks by John B. Bellinger III, the then Department of State legal adviser, at the London School of Economics: Legal Issues in the War on Terrorism (Oct. 31, 2006), at http://www2.1se.ac.uk/PublicEvents/pdf/20061031_JohnBellinger.pdf.
2 Harold Hongju Koh, Legal Adviser, U.S. Dep’t of State, Remarks at the Annual Meeting of the American Society of International Law: The Obama Administration and International Law (Mar. 25, 2010), at http://www.state.gov/s/1/releases/remarks/139119.htm.
3 John O. Brennan, Assistant to the President for Homeland Security and Counterterrorism, Remarks at the Harvard Law School Program on Law and Security: Strengthening Our Security by Adhering to Our Values and Laws (Sept. 16, 2011), at http://www.whitehouse.gov/the-press-office/2011/09/16/remarks-john-o-brennan-strengthening-our-security-adhering-our-values-an; John O. Brennan, Speech at the Woodrow Wilson International Center for Scholars: The Ethics and Efficacy of the President’s Counterterrorism Strategy (Apr. 30, 2012), at http://www.wilsoncenter.org/event/the-efficacy-and-ethics-us-counterterrorism-strategy.
4 Jeh Johnson, General Counsel, U.S. Dep’t of Defense, Dean’s Lecture at Yale Law School: National Security Law, Lawyers and Lawyering in the Obama Administration (Feb. 22, 2012), at http://www.lawfareblog.com/2012/02/jeh-johnson-speech-at-yale-law-school.
5 Eric Holder, Attorney General, Remarks at Northwestern University Law School (Mar. 5, 2012), at http://www.lawfareblog.com/2012/03/text-of-the-attorney-generals-national-security-speech/#mare-6236.
6 Stephen Preston, General Counsel, Central Intelligence Agency, Speech at Harvard Law School: Cia and the Rule of Law (Apr. 10, 2012), at http://www.cfr.org/rule-of-law/cia-general-counsel-stephen-prestons-remarks-rule-law-april-2012/p27912.
7 The reports and publications of the UK House of Commons Foreign Affairs Committee are available at http://www.parliament.uk/business/committees/committees-a-z/commons-select/foreign-affairs-committee/ Publications/. The reports cited here are available at http://www.parliament.uk/business/committees/committees-archive/foreign-affairs-committee/fac-list-of-old-wat-reports-/.
8 White House, the National Security Strategy of the United States of America 12-16 (2002), at http://www.au.af.mil/au/awc/awcgate/nss/nss_sep2002.pdf.
9 House of Commons, Foreign Affairs Committee, Foreign Policy Aspects of the War Against Terrorism, 2002-03, H.C. 196, para. t.
10 21 Apr. 2004, ParŁ. Deb., H.L. (2004) 356 (Lord Thomas of Gresford, statement opening the debate on international self-defense), at http://www.publications.parliament.uk/pa/ld200304/ldhansrd/vo040421/text/40421-07.htm.
11 Id. at 370-71 (Lord Goldsmith).
12 See, e.g., Select Committee on Foreign Affairs, H.C., Written Evidence Submitted by Daniel Bethlehem QC, Director of the Lauterpacht Research Centre for International Law, University of Cambridge, “International Law and the Use of Force: The Law as It Is and as It Should Be” (June 7, 2004), at http://www.publications.parliament. uk/pa/cm200304/cmselect/cmfaff/44l/4060808.htm.
13 House of Commons, Foreign Affairs Committee, Foreign Policy Aspects of the War Against Terrorism, 2003-04, H.C., 441-1, para. 429.
a The “reasonable and objective basis” formula—in paragraphs 5, 7, 8, 11, and 12—requires that the conclusion is capable of being reliably supported with a high degree of confidence on the basis of credible and all reasonably available information.
b The term “threatening”—in paragraphs 5, 6, 7, and 9—refers to conduct that, absent mitigating action, there is a reasonable and objective basis for concluding is capable of completion and that there is an intention on the part of the putative perpetrators to complete. Whether a threatened attack gives rise to a right of self-defense will fall to be assessed by reference to the factors set out inter alia in paragraph 8.
c The concept of direct participation in attacks draws on, but is distinct from, the jus in bello concept of direct participation in hostilities.
d The addition of the adjective “strong” to the “reasonable and objective basis” formula—in paragraphs 7 and 12—raises the standard that is required for the conclusion in question, given that this assessment would form the basis for taking armed action against persons other than those planning, threatening, or perpetrating an armed attack.
e Referred to as a “colluding state.”
f Referred to as a “harboring state.”
g As here described, referred to as a “reluctant host.”