I mean that isnt really true though, the uk is the second most powerful nation, infront of both China and Russia. Yes America is considered the most powerful nation right now but that only really because of its size. The uk has been around for a very long time, it has way more allies and social power. Also, although the uk isnt allied with china, china doesnt have problems with the united kingdom unlike with American. America is also allies with the uk as america knows that America allied with uk in a war would be a very powerful/unstoppable force. Thats why china and russia leave us alone. So yeah America is powerful, but don't downplay the other countries