what is there of the US to break up ? Hegemony not the same as empire .
China has got big troubles at present and I'm not convinced their system of government works in their favor long term but they will reamain a great power because of the size of their country and of their population .
Russia is seriously underperforming and if they ever got sustained good leadership they could be a great power economically (as they are not presently ),as well as militarily .
Yes empires come and go , although am hopeful we are moving out of the age of empires . Hegemony will always be strived for however .
