On 7 September 2015, the Prime Minister David Cameron announced to Parliament that he had authorised the killing of a British national, Reyaad Khan, an alleged ISIL fighter, in Syria on 21 August 2015. Two other alleged militants died in the strike. The killings were justified on the basis of self-defence. The Defence Secretary Michael Fallon stated that the Government would ‘not hesitate’ to conduct further attacks against militants suspected of plotting against the UK, despite the fact Parliament voted against British military action Syria, in August 2013.

Was the strike legal?

There are at least three significant areas which render the legality of the strikes dubious:

  • Was the use of force permitted under international law on this occasion, and in particular, was anticipatory self-defence justified by the allegations mounted against Khan et al?
  • On what basis was self-defence justified?
  • What investigatory and due process guarantees apply to the targets?


The Government has stressed at length that the strike was legal, invoking self-defence under Article 51 of the UN Charter as the justification for use of force on Syrian territory without its consent.

Yet the right to use force in self-defence is not unfettered: international law mandates that it must comply with the requirements of necessity and proportionality. Even if the strikes were necessary and proportionate, it is not clear whether there exists a right to anticipatory self-defence against non-state actors. In Palestinian Wall Advisory Opinion, the International Court of Justice (ICJ) took the view that the right is only available when the attack emanates from another sovereign state, as opposed to non-state actors not under the control of the host state (July 2004). Though the ICJ has since reaffirmed that view, it has been criticised as unrealistic given the threat of terrorism and state practice to the contrary.

There still remains a requirement that the attacks pose imminent risk. From the limited disclosure made, it can be derived that Khan and the others were alleged to be radicalised, recruiting sympathisers and seeking to orchestrate attacks against the UK. Whether that satisfies ‘imminence’ remains to be seen.

This is further compounded by the Government’s murky explanation in the aftermath. Before the House of Commons, the prime minister indicated that the strike was justified on the basis that these individuals presented a threat to the UK. However, the official communication sent to the UN Security Council provides that the strike was justified by the need to combat the threat ISIL presents to Iraq.

That inconsistency is of the utmost importance. It is not merely a pedantic point, but rather goes to the very heart of the rule of law: the Government has exercised lethal force against a British citizen without trial, in secret, and without a full presentation of the legal basis for that decision.

The lack of transparency also presents another difficulty: are these strikes taking place in the context of an armed conflict or law enforcement? That question will determine whether international humanitarian law (IHL) or international human rights law (IHRL) applies.

At the time of the strike, the Government maintained it took place outside the paradigm of armed conflict: the prime minister stated: ‘It was a targeted strike to deal with a clear, credible and specific terrorist threat.’ Such language would indicate that the law enforcement paradigm applies, so the protections under IHRL will attach to the lethal targeting of Khan.

However, in December 2015, some months after the strike, Parliament voted for military action in Syria. Since then, defence secretary has appeared before the Joint Committee on Human Rights to provide evidence on drone policy, where he stated that the UK was engaged in an international armed conflict with ISIL in Iraq and Syria. Here, there must be clarity as to the chronology. At the time Khan was targeted, there was no parliamentary authority in place for military action in Syria. Indeed, the prime minister’s statement to the House of Commons sought to assure Parliament that this was a counter-terror operation. When the defence secretary speaks of an international armed conflict in Syria, he must refer to the events that post-date the strike.

Thus, if the UK was not engaged in an armed conflict with ISIL in August 2015, then human rights law applies to the execution of Khan. This triggers three legal protections. First, the circumstances in which the Government can use lethal force will be significantly narrower than under IHL. Second, the individual target ought to have the benefit of robust due process guarantees. Third, where lethal force is used, the Government is under an obligation to conduct an effective investigation afterwards, with the European Court of Human Rights jurisprudence robust on this point, since McCann v United Kingdom.

Transparency as a partial solution

How to safeguard the rule of law? We must seek greater transparency from the Government. A possible mechanism that might assist could be to impose a statutory obligation on the Intelligence and Security Committee (ISC) to conduct a post-strike review where: (i) a strike has targeted a British citizen; and (ii) where a strike has resulted in the injury or death of a British citizen. The latter category would cover instances were civilians are affected as collateral damage.

The existing regime, contained in the Justice and Security Act 2013, allows for the ISC to conduct an inquiry in the following circumstances:

  • Section 2(1) provides that the ISC may examine or oversee the expenditure, administration, policy and administration of the Security Service, the Secret Intelligence Service and GCHQ; and
  • Section 2(2) provides that the ISC may examine such other activities of the Government set out in a memorandum of understanding.
  • Section 2(3) provides that the Committee can only consider operational matters provided it is not a part of any ongoing intelligence or security operation and is of significant national interest. Presently, it is not entirely clear if drone strikes have ceased to become ‘operational’ for the purposes of the 2013 Act. This further reinforces the need for a stand-alone requirement that the ISC conduct post-strike scrutiny; ongoing operations in Syria might preclude the ISC’s discretion to launch such an inquiry, further hampering accountability and transparency.


While it has been reported that the newly constituted ISC may conduct an inquiry into the drone policy of its own volition, this is not sufficient from a rule of law perspective. The defence secretary has indicated that there was no need to reform the law so that post-strike scrutiny would be automatically triggered:

‘I think we can rely on the Intelligence and Security Committee to do its work. It is in charge of its work programme. We recently strengthened its powers through the Justice and Security Act. The Government are going to co-operate fully with it. So I think really that is a matter for the Intelligence and Security Committee.’

Respectfully, that misses the point. The severity of the issues at hand cannot be left to a committee on a discretionary basis; there must be a mandatory safeguard in the UK legal system which provides for review as of right.

Such a proposal is not only desirable and useful but essential; the rule of law requires that power not be exercised arbitrarily. It cannot be acceptable that the Government can authorise the execution of citizens abroad without any independent oversight, a view that is shared by former DPP, Keir Starmer. Entrusting the ISC with post-strike scrutiny is also practical because it is a security-cleared, security-conscious panel of parliamentarians who already work with highly sensitive information. The infrastructure for sharing, redacting and securing intelligence information already exists, thus saving further cost and delay.

Post-strike scrutiny

The legality of drone strikes is so riddled with serious legal questions that the rule of law mandates a post-strike review in every case where a British citizen is executed without trial. Designating the ISC with this role is not, however, a panacea; it will address one aspect of the accountability vacuum. Nonetheless, the ISC is perhaps the best placed body to undertake this type of work, on an urgent and secure basis, given its unique role and relationship with the intelligence and security agencies.

This is an edited version of Emma Fitzsimons’ Bar Council Law Reform Essay Competition 2015 winning essay, ‘Rage Against the Machines: Post-strike scrutiny for targeted killings’. The full essay is available here.  

Contributor Emma Fitzsimons, pupil barrister at Garden Court Chambers