One may of course question whether such extraterritorial seizures can fall within the scope of self-defence. However, international law does not stipulate the means by which a state can defend itself. is that the actions taken are proportionate; that is, they do no more than is necessary to either put an end to an armed attack or, with one having already occurred, the taking of action against the perpetrators with the intention of staving off the threat of a future one. In this respect, and if one accepts that an action in self-defence is necessary, then the arrest and trial of a suspect would seem more agreeable from a proportionality angle then any whatsapp number list sort of bombing campaign against the suspect(s) which would raise the additional prospect of civilian casualties and physical destruction.
However, and in any case, while it is not known whether the Libyan authorities had the capabilities to take action against al-Liby, demonstrating that the Libyan authorities were either unable or unwilling to take the required action would be hard to do without showing that the US approached the Libyan authorities, making any action in self-defence arguably unnecessary and thus unlawful.
Finally, while the US has argued for the applicability of the unwilling or unable standard in the context of actions in self-defence, it has also in the same breath claimed that ‘Because we are engaged in an armed conflict with al-Qa’ida, the United States takes the legal position that – in accordance with international law – we have the authority to take action against al-Qa’ida and its associated forces without doing a separate self-defense analysis each time.’