Donald Trump has threatened Syria with a ‘big price to pay’ for an alleged chemical attack on 7 April in a Damascus suburb. Last year, in similar circumstances, Trump authorized an attack of 59 Tomahawk missiles that reportedly killed 9, including 4 children. The French and German governments responded with a joint press release finding it a ‘just and proportionate’ response. They did not say ‘lawful’–nor could they.
Armed reprisals are uses of military force that follow an incident, usually to punish or in retaliation or revenge and which do not fit the exception to the prohibition on the use of force for self-defence. See the same conclusion here and here. Reprisals need Security Council authorization to be lawful. The Security Council has never authorized a reprisal and will not in the case of Syria.
In 1970, the General Assembly stated clearly in its Declaration on Principles of International Law Concerning Friendly Relations and Cooperation among States that among the fundamental rights and duties of states, is the ‘duty to refrain from acts of reprisal involving the use of force’ against other States. The International Court of Justice found in its 1994 advisory opinion on the Legality of Threat or Use of Nuclear Weapons that ‘armed reprisals in time of peace […] are considered to be unlawful.’ In the Oil Platforms case, it further held that US attacks on Iranian sites were not lawful acts of self-defense because of their retaliatory nature.
Thus, unauthorized reprisals are always unlawful, and, indeed, as Derek Bowett wrote in a 1972 article in the American Journal of International Law: ‘Few propositions about international law have enjoyed more support than the proposition that, under the Charter of the United Nations, the use of force by way of reprisals is illegal.’ Nevertheless, Bowett preceded to construct an argument to reverse the ‘proposition’ eight years after the UK was condemned by the Security Council in Resolution 188 of 1964 for bombing Fort Harib in Yemen. The Council found the bombing an unlawful reprisal and ‘incompatible with the purposes and principles of the United Nations.’ (It is noteworthy and to the UK’s credit that it did not veto the resolution.)
Bowett had undertaken a similar effort at ex post facto justification when he came up with the ‘Caroline Doctrine’ to attempt to justify the force used in the 1956 Suez Crisis by the UK, France, and Israel. In reaction to the wide condemnation of the UK, he proposed a re-interpretation of UN Charter Article 51 on the right of self-defence reading out ‘if an armed attack occurs’ to replace it with a right to use force in cases of necessity that are ‘instant, overwhelming, leaving no choice of means, and no moment of deliberation’. Following 9/11 and the US declaration of a ‘war on terror’, the British government referenced Bowett’s argument as a better legal basis for using force than America’s assertion of global war. While perhaps an improvement on the ‘war on terror’, Bowett’s Caroline argument nevertheless conflicts with the Charter, a fact that is being underscored increasingly by scholars today.
Bowett’s arguments on reprisals have had and are likely to have far less influence. First, the US seems to have lost interest in providing legal justifications. None were offered in April 2017, and the new US National Security Adviser John Bolton published an opinion during the Kosovo crisis concluding that international law is an ‘academic sham’. Why bother making a weak argument where none will do?
This point in Washington has been reached after a long, steady decline in US respect for international law restrictions on the US of force. During the Cold War, the US tended to manipulate the facts, rather than the law. Respecting reprisals, the US tried to justify retaliatory attacks on Libya in 1986 as self-defence. Ronald Reagan ordered air attacks on Libyan military sites in Tripoli and Benghazi ten days after a terrorist bombing of a disco in Berlin. The U.S. said it had evidence that Libya was planning more acts of terrorism. On this basis, US government lawyers and scholars argued the bombing was lawful as self-defense under Article 51, though the facts fell far short of meeting the legal requirements. The Berlin incident did not amount to a significant armed attack per the standard set out in the Nicaragua case. Evidence of the necessity for military action was also lacking. Whatever vague evidence the U.S. had amounted to criminal plots, not armed attacks. The UN General Assembly condemned the Tripoli operation, the US not having the grace to abstain from using its veto in the Security Council.
With the end of the Cold War, US attempts at legal justifications began to noticeably dwindle. President Bill Clinton ordered unlawful armed reprisals on several occasions. In 1993, he ordered an attack on government buildings in Baghdad in response to an alleged attempt to assassinate former President George H.W. Bush. In 1996, when Iraqi troops moved against Kurdish separatists in northern Iraq, Clinton ordered attacks in southern Iraq. The US and UK actually tried to argue that these attacks on Iran were lawful under the UN Security Council resolutions that had been adopted against Iraq following its invasion of Kuwait in 1990. (Yes, the same argument the two States tried in 2003 when invading Iraq.) France and Russia disagreed in 1996 that resolutions connected with Kuwait’s liberation could justify the use of force years later for very different purposes. Even if the US and UK did have some sort of Security Council authorization, bombing southern Iraq to retaliate for action against Kurds in the north violated the principles of necessity and proportionality.
Clinton also carried out unlawful reprisals following terrorist attacks on the United States embassies in East Africa. He ordered missile attacks on Sudan and Afghanistan, which were a significant step beyond Reagan’s attack on Libya for state-sponsored terrorism. The US said the target in Sudan was a chemical-weapons related facility producing inputs for VX nerve gas. Many States condemned the air strike when the site turned out to have no connection with chemical weapons.
With 9/11, US justifications for using force became ever more attenuated variations on self-defence. In 2013, when Barack Obama sought Congressional authorization to use force in Syria following a use of chemical weapons, he asserted that a military strike was somehow linked to US national security. The Republican-controlled Congress refused to give him authorization, not because of the flimsy legal basis but because Republicans did not wish to give Obama a win.
At least Trump is no hypocrite. He offers no legal basis for attacking Syria other than to enforce the law in the case of a war crime. In other words, he plans to violate the prohibition on the use of force to send the message of how important it is to comply with the law on chemical weapons. And he is doing so with relish as he tweets, ‘Get ready Russia, because [the missiles] will be coming, nice and new and “smart!”’
French President Macron has actually chosen to encourage Trump and Britain’s Prime Minister May is still considering options. There should, however, be only one option for States committed to the rule of law: Use the means available in international law to seek accountability for law violations. It is a dangerous moment in history to do anything else.