It is not pusillanimity. If you are the lone society that tries to cooperate and spread peace you will be eaten out. It is rational and logical behaviour to survive.
Of which society do you speak of? The US?
These are bad actions but for "the greater good"? You don't get to have it both ways. Protecting yourself without torturing people is 100% feasible and your argument should only be heard in a war crimes tribunal from the defendant'a lawyer to ease their sentence.
Morality isn't hard, but the implementation can be.