I've been thinking about all the wars that the USA has been involved in since I was born in 1946: Korea, Vietnam, Panama, Dominican Republic, Grenada, Sudan, Lebanon, Croatia, Iraq (I'm thinking that there may be more that I haven't remembered).
OK technically they weren't all wars. OK none of them were technically wars. All most all of them were to maintain American hegemony in various parts of the world.
Why is it that we keep thinking that we are defending anything other than our hegemony? Because we are just too exceptional, of course. We would not do that, therefore, we don't. Ergo.