[liftbigweights]

> The USA has the first military power in the whole world and could go and invade a bunch of countries if they wanted to and nobody would oppose them.

This is false. Have you heard of the korean war or the vietnam war? Or the afghanistan/iraqi war? There are ( and have been ) powers that opposed the US ( sometimes successfully ). Look at current day syria.

> Since they are not doing so, its hard to call them belligerent.

What? We have been in a state of perpetual aggressive war ever since ww2 ( frankly since the american revolution war if we are being honest ).

> The British Empire was way worse than the USA all things considered.

It may or may not have been worse. But being belligerent isn't a relative matter of comparison. It's a matter of state. It's like being pregnant. You are pregnant or you are not.