This afternoon in the House of Commons the Prime Minister told MPs that Reyaad Khan, the “Islamic State” fighter from Cardiff, was killed in Syria in a targeted RAF drone strike. His death was reported some days ago but it was not clear till now that it the RAF had targeted him. The case raises several issues, but I agree with what the PM said the Attorney General advised — that this operation was lawful.

The Attorney General’s advice

The normal convention is that ministers do not refer publicly either to the fact that the Law Officers have been consulted, or to the content of their advice. But David Cameron departed from this convention, saying the Attorney General had been consulted and had given positive advice.

In a sense this was inevitable: once the PM had given MPs his view of the legal basis for the attack, it would have been politically impossible to leave in any doubt whether or not the Attorney had been asked, or had agreed. It’s not clear at all that the usual non-disclosure can be maintained at all in future in cases involveing the use of force abroad (something I expect the Chilcot inquiry to make recommendations on).

International law

The PM said Khan was plotting terror attacks in the UK, so the strike was an act of self-defence under article 51 of the UN Charter. It provides—

Nothing in the present Charter shall impair the inherent right of individual or collective self-defence if an armed attack occurs against a Member of the United Nations, until the Security Council has taken measures necessary to maintain international peace and security. Measures taken by Members in the exercise of this right of self-defence shall be immediately reported to the Security Council …

Mr Cameron made clear that the government will be writing to the UN Secretary General today to report this as an act of self-defence. But is it?

The first question is whether anything planned by “IS” against Britain would have been an “armed attack”. In the Nicaragua case, the International Court of Justice held that not every incident involving force will amount to an “armed attack” justifying self-defence: but said (para. 195)

The Court sees no reason to deny that, in customary law, the prohibition of armed attacks may apply to the sending by a State of armed bands to the territory of another State, if such an operation, because of its scale and effects, would have been classified as an armed attack rather than as a mere frontier incident had it been carried out by regular armed forces.

The ICJ’s point here is to make clear that not every minor border incident justifies the use of serious retaliatory force.

But of course the bombing of civilians in a British city would, if carried out by (say) French forces, be classified as an armed attack because of its scale and effects. So, while there’s room for critics of the RAF strike to quibble about this and ask for more details about what intelligence there was and what Khan was planning, it seems to me that any substantial terrorist plan would easily meet the threshold.

Some would argue that an armed attack has to be by a State, or attributable to one, before the UK can defend itself. Here, the RAF’s attack violated Syrian sovereignty but Khan’s plans, whatever they were, can’t obviously be blamed on the Syrian regime. But I don’t think this is a strong argument against the UK .

If the inteference with Syrian sovereignty involved in this attack must be justified by the attribution of some Syrian blame for Khan’s plans, then the fact that Syria was “unwilling or unable” to stop him provides that justification. As I argued last year,

international law must permit a state under attack to respond to and defeat its nonstate enemy, even on the territory of another state, if that state is unable or unwilling to help it.

In any event, the insistence that self-defence can only be invoked against sovereign states seems to me unreal after 9/11. Either international law on the use of force is an ass, unfit for purpose in the 21st century; or its principles must be capable of application to today’s real threats to peace and security. I think the latter.

There’s an interesting discussion of both the “scale” and “state” issues by Karl Zemanek at the Max Planck Encyclopedia of Public International Law.

Finally, it may have occurred to you that none of Khan’s plans seem to have been implemented — so where’s the “armed attack”? A fair point, but customary international law has long recognised that pre-emptive self-defence can be lawful under the “Caroline” principles, where the

necessity of self-defense was instant, overwhelming, leaving no choice of means, and no moment of deliberation

words which again allow room for quibbles, if applied in a literal way. Was there an instant, overwhelming need to kill Khan at that moment? Could his plans not be averted by police action in the UK? Surely there was a moment of deliberation if the Attorney General could advise? I think these would be pretty weak attempts at hair-splitting.

If there was intelligence that Khan was involved in substantial “IS” terror plots, then it’s reasonable to see stopping him (rather than just stopping his plans individually, “downstream”) as an overwhelming necessity. No other means of stopping him is available to Britain in lawless Syria. And once he was located, the necessity to act became instant, since another chance to stop him might not come.

Of course the use of any force must be proportionate; and this was. No civilians were killed in the attack, so it’s impossible to argue that civilian casualties were disproportionate to the military advantage gained.

Human rights law

International law isn’t the only thing to consider, though. There’s also European human rights law, and our own domestic law.

The European Convention on Human Rights does not apply to this killing. Applying the principles laid down in Al Skeini v UK (see para. 130-142), Britain did not exercise control and authority over Khan, or effective control over the area he was in. The article 2 Convention right to life does not, therefore, apply. It’s not even necessary for the UK to rely on article 2.2(a), which permits killing in defence of others, either in the European Court of Human Rights or in our own courts under the Human Rights Act.

Domestic criminal law

Finally, the Attorney General’s advice would have considered the law of England and Wales if the drone that killed Khan was operated from within this jurisdiction; or if some commander based here gave the order or participated in the decision.

It’s an offence in this country to murder a British citizen abroad, under section 9 of the Offences Against the Person Act 1861; and this was, obviously, an intentional killing. It was however lawful on the basis of the principle we refer to as “self-defence”, but which is actually wider: you can use reasonable force in defence or yourself, or another person or property.

It was also lawful because of the statutory defence in section 3(1) of the Criminal Law Act 1967, which says—

A person may use such force as is reasonable in the circumstances in the prevention of crime …

There can be no doubt any terror plans Khan was working on would have involved crime. The only remaining question is whether killing him by a drone strike was reasonable in the circumstances.

That, of course, is a question of judgement. But assuming the RAF thought Khan’s plans involved killing a number of civilians it seems hard to say otherwise — especially since under section 78(3) of the Criminal Justice and Immigration Act 2008

The question whether the degree of force used by D was reasonable in the circumstances is to be decided by reference to the circumstances as D believed them to be

and since under section 78(4) an honest belief is ultimately enough on which to base the defence, even if it is mistaken or unreasonable.

The law is, in short, that it’s lawful to use force proportionate to a threat you honestly believe someone presents. And it’s lawful to do so pre-emptively because, as Lord Griffiths explained in the Privy Council’s judgment in 1987 in Beckford

a man about to be attacked does not have to wait for his assailant to strike the first blow or fire the first shot; circumstances may justify a pre-emptive strike.

There seems to me no question but that this was a lawful killing in terms of domestic criminal law.

The emerging convention on approval of military action

The final legal point raised by this incident is one of constitutional law, and the emerging constitutional convention that the government does not order the use of military force abroad without the approval of the House of Commons. The PM has previously argued that

you should consult the House of Commons as regularly as you can and the House of Commons should have an opportunity to vote. The point I always make, though, and this is not to run away from the right hon. Gentleman’s particular scenario in any way, is that it is important that a Prime Minister and a Government reserve the right to act swiftly without consulting the Commons in advance in some specific circumstances—for instance, if we had to prevent an immediate humanitarian catastrophe or, indeed, secure a really important, unique British interest. But other than that I believe it is right, as he said, to consult the House of Commons.

and today he relied on this flexibility, in circumstances where it obviously wasn’t possible to ask for a vote before making the strike.