Much to the resentment of the US for two hundred year Britain was the Sheriff of the World,  keeping law and order.  After Britain was bled dry fighting for others in WW1 and WW2 the US  felt they should have the honor. Now they've got it they are realizing that it's not so easy and are making a mess of it.  One of the problems is the US always wanted  to appear to be the nice guy, the Brits had no such allusions .