The U.S. strike in Iraq that killed Soleimani was in violation of UN norms proscribing such unilateral use of force
The killing of Iranian General Qassem Soleimani near Baghdad in drone strikes carried out by the U.S. earlier in January raised the spectre of war in West Asia. Later, U.S. President Donald Trump threatened to attack cultural sites in Iran in the event of reprisals by Tehran. The next week, Iran retaliated by carrying out missile attacks on two facilities housing U.S. troops in Iraq. These incidents give rise to some interesting legal questions: Was the U.S. attack on Soleimani legally justified? And can cultural sites be legitimately attacked in any armed U.S. response?
Under international law, there is a general prohibition on the use of force, articulated in Article 2(4) of the UN Charter. The Article proscribes any use of force by members against the “territorial integrity or political independence” of a state. However, the Charter recognises two limited exceptions: first, in the use of force by a state in the lawful exercise of its right to self-defence; and second, when such an act is carried out with the prior authorisation of the UN Security Council (UNSC) and acting pursuant to the Council’s emergency powers “to maintain or restore international peace and security”.
Without prior consent
The use of force by the U.S. in Baghdad to kill Soleimani without prior consent from Iraq or the UN was, hence, a violation of such proscription, unless the U.S. can justify it as a lawful exercise of its right to self-defence. Not surprisingly, the Donald Trump administration was quick to claim that the killing was in exercise of its right to “anticipatory” self-defence. Mr. Trump claimed, without any further elaboration, that Soleimani was planning “imminent and sinister” attacks against U.S. diplomats and personnel.
The legal basis for “anticipatory” self-defence remains deeply controversial and contested. There are both legal and policy arguments against recognising a right to anticipatory self-defence. First, Article 51 of the UN Charter recognises the inherent right of every state to use force in self-defence, only “if an armed attack occurs”. Second, unlike an “armed attack”, which is an objective standard, an “anticipated” armed attack is a subjective one, open to abuse by states. Since the object and purpose of the general prohibition on the use of force is to minimise resort to unilateral use of force, a stricter and restricted notion of the right to self-defence is perhaps more appropriate.
Those arguing in favour of a right to anticipatory self-defence, however, stress on its customary character and frequently reference the Caroline incident. In 1837, British militia from Canada crossed into U.S. to set ablaze the ship Caroline, which had been used to ferry American insurgents that had mounted attacks in Canada. In diplomatic correspondence following the incident, the U.S. Secretary of State noted that Britain must show “a necessity of self-defence, instant, overwhelming, leaving no choice of means, and no moment of deliberation”. In reality, the destruction of Caroline was a response to an attack and its expansion rather than for averting any not-yet-mounted attack. Moreover, the incident took place before the conception of the UN Charter.
An anticipatory move
Nevertheless, contemporary Western scholarship, in view of the rise of terrorism and advancement of weapons technology, continues to advocate for a right to anticipatory self-defence. However even assuming that any such right has come into fruition, its contours are to be narrowly understood. As indicated, the threat of an armed attack must be so imminent that the need to act in self-defence should be “instant, overwhelming, leaving no choice of means, and no moment of deliberation”. The legality of the Trump administration’s decision to target Soleimani through drones in Iraq would, therefore, hinge on the disclosure of facts with regard to the imminence of a planned attack. Moreover, the administration will have to show that the strike was proportional to such (imminent) armed attack and necessary to respond to it. It will also have to justify its use of force in Iraqi territory and prove that Baghdad was either unable or unwilling to prevent the imminent attack. Finally, the U.S. will have to provide an explanation for the use of drones during peacetime, which resulted in collateral casualties.
Further, Mr. Trump’s specific threat to target cultural sites in Iran was in breach of the 1954 Hague Convention for the Protection of Cultural Property during armed conflict. It also violated UNSC Council Resolution 2347, sponsored by the Trump administration, which in the context of the Islamic State (IS) invasion declared that destruction of cultural property would constitute “war crimes”. It was therefore not surprising that Pentagon distanced itself from Mr. Trump’s position.