I find both Diaper N and Bryan both have correct and well thought out answers.
The "Cold War" one was with guns and bombs aimed at each other.
Now we have bonds and credit cards aimed at each other.
Britian ruled the world for about 100 years,
America ruled the world for about 40 ? or 50 ? years.
China will be the major influence for 10 or 20 years.
and probably India will come up next for 10? years.
It will get shorter and shorter and bounce around a lot more.
China needs us to buy their stuff.
We need China to make cheap stuff.
We're tied together and can't break up, or we both go down the tubes.
China's next big problem is it's people and what happens when they start seeing our old "Happy Days" and "Leave it to Beaver" reruns. They will want the "American Life" and will start to have an Arab Spring type event of their own over the next 5 years? JMHO.
so both Bryan and Diaper N have great answers.