As the whole world now knows, Osama bin Laden was killed by U.S. special forces yesterday, in a raid on his compound in Pakistan. Let me be clear at the outset of this post: I am not weeping for Osama bin Laden. bin Laden was a vicious terrorist mastermind and the leader of an evil organization that has wreaked havoc throughout the world, not least upon the Western psyche. As many have already said, the world is indeed a safer place now that he is dead.
That said, what international law issues arise? States are not normally permitted to exercise enforcement jurisdiction on the territories of other states, which is generally regarded as a serious sovereignty violation. In this case, while some initial reports I read last night suggested that Pakistan had been unaware of the operation, the Pakistani government has since stated that it was fully cooperative with what it now calls a joint effort. So no problems there.
How to characterize this act? I expect there will be some linking of it to the development of the notion of "targeted killing" as an instrument of international humanitarian law. However, to the extent that practice has any legitimacy (and it is highly controversial), it is only within the scope of the law of armed conflict. Osama bin Laden was not a participant or "combatant" in an armed conflict of the type known to the law. He was simply a criminal, albeit probably the most wanted criminal in the history of the world.
Accordingly, I'm drawn to the conclusion that this was simply an extra-judicial killing: state agents (including President Obama and Pakistani authorities) murdering an individual whom they regard as dangerous. Naturally, it is a blatant violation of international human rights law, which forbids governments killing civilians (even criminals) outside the lawful imposition of the death penalty (i.e. after a trial). Of course, neither the U.S. nor Pakistan has ever let international human rights law get in the way of accomplishing important foreign policy objectives.
And it's important not to be Pollyanna-ish about this; this kind of thing goes on all the time, though usually in secret and not trumpeted to the world. Moreover, given the fact that it's bin Laden, it's highly unlikely that any significant numbers of states will want to call either the U.S. or Pakistan to account, outside those with jihadist constituencies they wish to appease.
And perhaps, if there's a worry, that is it. We can be happy that bin Laden is out of the picture, but perhaps we should be concerned about powerful states being able to kill a person they deem to be really, really dangerous, publicly and without accountability. Is this a power we want to see other states exercising, such as China, Russia, Yemen, Pakistan itself? While most of us agree about how dangerous bin Laden was, perhaps many would not agree with China's assessment of why some particular dangerous person (say, a human rights activist?) had to be killed. Yet now, China can point to President Obama and say, if he can do it, why not us? Possibly, just possibly, a dangerous precedent.