Osama bin Laden was killed by US special forces in Pakistan on May 2 2011. Was this killing legal?
The first question to ask, I think, is whether bin Laden (and international terrorists in general) are to be considered criminals or enemy-combatants as defined in international law.
If they are to be considered criminals, they have to be dealt with in a court of law. But it is questionable at best that the US military or police do have the authority to capture someone in a foreign country without cooperating with local police. On the other hand, if international terrorists are to be considered enemy-combatants and bin Laden indeed didn’t make his surrender clear, then the killing was lawful.
Unfortunately, there isn’t even an internationally binding definition of terrorism. And for a person to be considered an enemy combatant under classical international law, there needs to be a war between two or more states or a civil war.
What I’m calling for is an extension of international law and a strengthening of the International Criminal Court (ICC) which prosecutes individuals for genocide, crimes against humanity, war crimes, and the crime of aggression. A first step must be for all states of the world to recognize the ICC and ratify its convention. A second step would be to provide the ICC with its own police force to get hold of the individuals that are under warrant. Possibly existing military forces of member countries (e.g. US) could be used if they were to get permission from the ICC.
That way, the prosecution of bin Laden could have taken place as follows:
The ICC opens an investigation
The ICC issues a warrant for bin Laden
Forces with a clear mandate under international law try to capture him
If he resists arrest and is killed that’s handled similar to when a national police officer kills someone upon resisting arrest. If bin Laden is successfully arrested he’s put on trial by the ICC.
Violent dictators such as Muammar Gaddafi could be handled similarly if they are committing crimes against humanity or equally grave crimes under international law. I see no reason to wage war against a whole country if the problem lies in the leadership.