I suppose it is true to say that the world is a better place without Khamenei thus justifying his killing
Can't argue with the first part; I won't miss him. But, "justifying his killing"? I know recent US presidents have enjoyed flexing their muscle targetting people they didn't like for murder, but it is hardly justified.
That was the point I was making.
Apart from anything else, Ford's EO of 50 years ago is still in force. Ford was horrified of course by Kennedy's murder and some of the outlandish theories (CIA involvement etc) which were being promulgated, and by the accounts of CIA plots to kill Castro. (I seem to remember exploding cigars.). In February 1976 Ford ordered that "no employee of the United States Government shall engage in, or conspire to engage in, political assassination." Subsequent presidents (Carter and Reagan) removed the word 'political' but the substance remained in force and both Bushes and Clinton left it in place.
Presidential Executive Orders remain in place until specifically revoked unless there was a time limit imposed on the original EO.
They can say what they want, but doubt ,any buy it who didn't already buy it before. But face it, in every war the name of god (by whatever name (s)he is known) is invoked by all sides, and the troops are told they are doing god's work. It's pretty much a requirement