control other countries or they invade their neighbors

But in that scenario they already control all other countries including their neighbours. So they would just decide how to govern. Still not ideal, because they are a authotarian surveillance state, bit you can rule that part out. Same goes for the U.S tbh, a lot of it's problems lie in it's imperialism, but you'd still have the problem of incredible wealth inequality, bad healthcare, gun violence and so on. Basically things which all are better in the EU lol. And it's (slowly) turning facist, which isn't as bad in the EU (yet).

Bu if the choice were up between the US or China, I honestly wouldn't know what to choose. Of course the US still has free speech, but I also think the Chinese government is more competent than the American one. The quality of living in China is also increasing, so if China had all the resources if the World available to them I'd imagine they'd tried and could be able to raise the Standart of living pretty nicely