There are three countries in the world that stand out for a few reasons - the first being size. The second is resources which is very much related to size. A third has to do with the population and the advancements made possible by those people. A fourth has to do with geography. You know those three countries are Russia, China, and the US. You also know that the US stands out as being the one that best developed scientifically, commercially, and in many other aspects - militarily being one of them. You also know we derive a lot of security by being bounded by oceans and friendly neighbors - one very much like ourselves. China and Russia were just big oafs by comparison because their people were constrained by feudalism where we are were driven by an individual and competitive spirit to achieve. The only competitive forces in that respect for a long time were the European powers, but they had to rely on colonialism to supply the critical mass they lost in size.
The point is that the three countries all have good and bad points. Because of communism and the zeal to spread it across the globe, we became the only country with the ability to counter Russia and China. Like it or not, that's the way the cookie crumbles. I don't think you'd like the world very much if we hadn't stood up to the Soviet Union, and now it's turning to a US China struggle. You can be complacent and belittle or resent our past and current policies (and I'd agree with you about some of them), but we add balance. Personally, I see Islam as much an evil as communism, but it's a religion ... and, therefore, we must respect it. Still our efforts in the deserts of the world are going to be as wasted and futile as the Crusaders. I'll hold the Vietnam and Korean conflicts differently while agreeing that both, and particularly Vietnam, were poorly prosecuted.