Where terrorism threatens international peace and security, the Security Council is the natural body in which to consider claims of amnesty or immunity. The historical precedent, a 1937 League of Nations Convention to establish an international criminal court to prosecute international terrorism, did not maintain centralised control over amnesty decisions concerning international terrorism, but instead endowed the state responsible for enforcing the penalty against an offender with a right of pardon, to be exercised after mere consultation with the president of the court.^[59] The drafters of the Convention rejected an alternative proposal to give the League Council the right of pardon, to be exercised on the motion of the state in which the sentence was to be carried out, the state against which the terrorism was directed, or the state of which the offender was a national.^[60]

Under the modern law since 1945, the UN Charter posits peace and security as higher values than justice, given its comparatively fleeting references to human rights in Article 1(3) (in contrast to detailed provisions on collective security enforcement under Chapter VII), the extensive preservation of domestic jurisdiction and national sovereignty, and the absence of explicit provisions on humanitarian intervention. Charter obligations prevail over other treaty obligations,^[61] and the certainty of treaty responses to terrorism may need to yield to exceptional security interests. For example, at the provisional measures phase in the Lockerbie incident, the International Court of Justice (ICJ) accepted that Libya’s rights under an anti-terrorism treaty (to prosecute rather than extradite a national) would likely impair the rights enjoyed by the UK and US under Security Council Resolution 748 (which demanded the surrender of the suspects to those countries).^[62] It is clear that the drafters of the Charter anticipated exceptional circumstances where the maintenance of peace and security might conflict with efforts to remedy serious violations of human rights, including through international criminal justice processes. While it might be hoped, as former UN Secretary-General Kofi Annan writes, that ‘[j]ustice and peace are not contradictory forces’ but forces that ‘promote and sustain one another’,^[63] it cannot be ruled out that exceptions to that rule will arise.

In relation to ICC prosecutions of potential terrorism offences, Article 16 of the Rome Statute explicitly recognises the Security Council’s competence in security matters by providing that the Council may postpone the investigation or prosecution of an international crime for a renewable 12-month period.^[64] The Council has relied on this provision to preclude temporarily the investigation or prosecution of ICC crimes by personnel from states not party to the Rome Statute engaged in UN operations.^[65] While this particular measure has been criticised on a number of legal grounds,^[66] it illustrates that a practical mechanism for managing the potentially competing interests of international justice and international security has been built into the ICC. The use of that mechanism may be perceived as legitimate where there is specific justification of the need to postpone the investigation or prosecution of a particular case to meet demonstrated security needs, in contrast to the foregoing example where the Council has given blanket immunity to a whole class of people without an individualised assessment of the relative interests of justice and security at stake.

Council interference with treaty frameworks is not to be lightly presumed, and the discontinuance of the Lockerbie case in the ICJ ensured that the question of the availability and conditions of review of Council measures that conflict with other treaty obligations remain undecided. Like political decisions to grant pardons or amnesties generally, Council decisions of this kind are not outside the realm of law; indeed: ‘[a] discretion can only exist within the law’.^[67] If a duty to prosecute terrorism, or not to confer amnesties for serious crimes, were to emerge as a norm of jus cogens, then the Council may be prohibited from conferring amnesties,^[68] if it is accepted that the Council cannot lawfully override norms of jus cogens.^[69] Respect for jus cogens norms is arguably an outermost limit on the Council’s security powers, even in its efforts to confront the serious threat of international terrorism.

The International Criminal Tribunal for the former Yugoslavia has specifically suggested that the jus cogens character of the international crime of torture would not permit a national amnesty to preclude an international or foreign prosecution,^[70] although whether it would also displace a Security Council amnesty is less clear, given that the question of conflict of a jus cogens norm and a Chapter VII Security Council measure has not been definitively settled by any superior international court. State participation in anti-terrorism treaties may also be less attractive if they do not offer certainty and predictability, due to vulnerability to Council interference. There is the further danger that powerful states may attempt to circumvent treaty regimes by pursuing Council measures. At the same time, the Council’s broad discretion under the Charter cannot be unduly fettered in dealing with serious terrorist threats to security, and criminal law responses may not always be the appropriate solution.