As far as our government is concerned, our international actions should be ruled by the Law of Nations.
§ 73. The acts of individuals are not to be imputed to the nation.
However, as it is impossible for the best regulated state, or for the most vigilant and absolute sovereign, to model at his pleasure all the actions of his subjects, and to confine them on every occasion to the most exact obedience, it would be unjust to impute to the nation or the sovereign every fault committed by the citizens. We ought not, then, to say, in general, that we have received an injury from a nation because we have received it from one of its members.
§ 74. unless it approves or ratifies them.
But, if a nation or its chief approves and ratifies the act of the individual, it then becomes a public concern; and the injured party is to consider the nation as the real author of the injury, of which the citizen was perhaps only the instrument.
§ 75. Conduct to be observed by the offended party.
If the offended state has in her power the individual who has done the injury, she may without scruple bring him to justice and punish him. If he has escaped and returned to his own country, she ought to apply to his sovereign to have justice done in the case.
Law of Nations, Chapter VI., Emmerich de Vattel
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All in all, it's a very complicated question -- and one that shouldn't be glossed over, in my opinion.
Agreed....but you will find a great many people who will flambe` anyone who mentions the ends may not always justify the means.
Of course none of this applies. The acts of OBL and his followers are extrapolated to all of Islam and they are de facto guilty with no evidence at all /s