At least so far, they have been expanding economically and not militarily, as the US. China could easily start wars with anyone they wanted, and they haven't done so. The US on the other hand, has wars all over the place.

I don't know, and I cannot know. I can only hope.

They could not easily have done so, because the US was undisputed top dog. And they are spending huge sums militarily, including on nukes.