The US is like any other country in that it will act on its own self-interest. That is basically all there is to it. Now, whether the policies that it pursues to that end are meaningful or not depends on a lot of things, including, but not limited to, the State Department, White House, CIA etcetc. So, there will be some amount of inconsistency in US policy over time, depending on the nature of people who run the ship.