In light of these general principles, it is important to note that amnesties for terrorism may raise different issues than those applying to existing international crimes. To begin with, there is not yet any general international crime of terrorism, so that acts of terrorism do not automatically trigger the same kind of legal analysis as war crimes, crimes against humanity or genocide, which have well-developed international legal frameworks and institutional responses (including the ICC, which does not, by contrast, have jurisdiction over terrorism).

Certain manifestations of terrorism have, however, been addressed by 13 sectoral anti‑terrorism treaties, prohibiting and often criminalising physical acts such as hijacking, hostage-taking, bombings or the misuse of nuclear material. Those transnational criminal law treaties typically establish ‘prosecute or extradite’ regimes for the relevant offences, but fall short of creating customary international law crimes attracting universal jurisdiction under general international law (with the possible exception of the most well-established sectoral offences of hostage-taking and hijacking, which exist as parallel customary law prohibitions).

Since 9/11, the international community has increasingly regulated ‘terrorism’ directly through the enforcement powers of the UN Security Council, which has required all states to criminalise terrorism in domestic law.^[51] Terrorism is, therefore, of significant concern to the international community, and so the question of amnesties for terrorism arguably now attracts the interest of international law and cannot be left to domestic jurisdiction alone. At the same time, isolated or low-level terrorist acts of a purely domestic character may raise different considerations than high-intensity acts of international terrorism, and the latter will inevitably engage more issues of international law and policy than the former.

In many cases, war crimes or crimes against humanity will be typically more widespread and affect larger sections of the population than terrorism, and so amnesties for terrorism may not be justifiable as necessary to achieve national reconciliation or to restore harmony between rival ethnic or religious groups in the community. Indeed, prosecuting terrorism is often necessary precisely because terrorists attack the institutions of the state and the community that the state protects. State practice confirms that the international community considers terrorism wrongful precisely because it undermines the stability of political structures within which the life of the community may take place.^[52] It may be questioned, for example, whether it was proper in 2005 for the King of Morocco to pardon seven Islamists convicted of involvement in the May 2003 terrorist attacks in Casablanca, which killed 45 people.^[53]

On the other hand, amnesties for terrorism may be appropriate where conflict is sectarian and affects significant parts of the population, or in specific cases where life is at imminent risk. In an effort to defuse a violent and widespread Islamist insurgency, in 1999 Algeria passed a Law on Civil Concord, which offered immunity from prosecution for insurgents who demilitarised. Immunity was not available for those who participated in collective massacres, rapes, or public bombings. Claimants were assessed by a three-member panel of judges and officials, and received housing and integration assistance if successful. The law was overwhelmingly approved by 98 per cent of Algerian voters.^[54] As a result, 4500 insurgents laid down their weapons.

By 2005, Algeria estimated that around 1000 insurgents remained. To entice them to demilitarise, the government put a Charter on Peace and National Reconciliation to referendum in September 2005, which was endorsed by 97 per cent of voters.^[55] The Charter on Peace and National Reconciliation pardons those convicted or imprisoned for armed violence or support of terrorism. It also offers amnesties to those who renounce violence and disarm; those who were involved in networks of support for terrorism and who declare their activities to the authorities; and those sought in Algeria or abroad who present themselves to the authorities. Pardons and amnesties are not available to those involved in collective massacres, rapes, or public bombings. While human rights organisations have been critical of the Charter on Peace and National Reconciliation,^[56] the real concern is not so much its text as the apparent failure of Algeria to seriously attempt to bring to justice those suspected of committing the serious crimes exempt from pardon or amnesty.

International terrorism affecting multiple states may require different analysis than predominantly domestic terrorism of the kind experienced in Algeria. Where terrorist acts affect multiple states, waiving prosecution or extradition should ‘only be exercised in agreement between the nation and the states whose citizens and property are the object of the terrorists’ acts’.^[57] Illegitimate reasons for failing to bring terrorists to justice might include appeasement, fear of reprisals, or the protection of commercial interests.^[58] The more serious the terrorist acts involved, the stronger the justification must be for waiving prosecution or extradition. Such decisions should not be taken arbitrarily or unilaterally, but should be based on a careful balancing of vital community interests, such as humanitarian needs, justice for victims, long-term peace, or sustainable political solutions.