correct
The laws refer to Heads of State if I remember correctly. Bin Ladin may be a leader, but he is no Head of State.
We could not go after Sadam Hussein directly, but we certainly bombed enough of his bunkers in hopes that he might be in one of them.
How-about rather than change our laws, amend them to require the UN to put a figurative price on a Head of State's head before the US takes him out. This way appropriate world-wide checks and balances are still in place.
-Steve G.