So the bourgeoisie have money invested in all countries, so no matter who win or loses, they make a profit. However, the USA sabotages other imperialist powers to keep its status as a hegemon, but why does it do that when it doesn’t really matter which imperialist is the hegemon when all the bourgeoisie make profit regardless?
This is covered in Lenin’s Imperialism: The highest stage of capitalism. To paraphrase, the bourgeoisie is not a homogeneous group, especially across borders. They are in competition with the bourgeoisie of their nation and other nations for their share of wealth too.
Hopefully someone will give a more well sourced answer as I don’t have time to look up the passages from the text right now.
What else is left for the US bourgeoisie to do when infinite growth is impossible but demanded by capitalism?
So you are saying that even though they have money invested on them, sabotage is more profitable?
Yes, the military-industrial complex is a quite powerful industry. Also, note that capitalism doesn’t necessarily advocate logical decisions — socialism would be better for everyone even in a selfish perspective, because oppressed people might be inventing things like cures for cancer that even the bourgeoisie want…