Would it not be the equivalent of a what supremacist gang get into the army and get trained and do a couple tours here and there. Comeback home and all go to Canada and pull off a deadly attack? Should the US be blamed for training the group that messed up Canada? Or does the US get a pass because we are a hegemony?
Pro Tip: When you are wanting to ask a Why question, its a good practice to make sure the What part is accurate. Especially when it includes a broad generalization. Have a blessed day!