Make a list of those nations that are not truly our friends and there are very few that truly are, and yet we have perforce dealings with them for various reasons, including, Pakistan, Saudi Arabia, Egypt, Russia, etc

Of those nations that are our friends, what you find is that we do their militaryh protection, mostly, via our bases or forces, as in England, France, japan, S. Korea and on and on (some 750 bases!).