It's China, China, China. Even though all those Russian weapons are still a huge problem...
In many ways China has the potential to be more powerfull and dangerous than the USSR ever was.
They have a huge, homogenous population with a rubust, growing economy. And located in a very differnt geographical area than Russia. Very skilled and dedicated workers. Great tech know how, etc. Soon to put men into space and even on the moon... Already China is the world's third largest nuclear delivery system.
One thing is very different between our relations with the USSR and China. I don't think there was a strong hatred directly between the pople of the US or the USSR. I think there was, and is, a general feeling that the people were pretty much the same. It was more of a struggle between political ideologies (communism/socialism vs. demoracy).
This may not be true with China. Unfortunately, race and race hatred is still a big motivator in the world. It may be easier for the US and China to hate each other in a very fundemental way because of the obvious physical/cultural differences. Even though religion was not a part of the USSR (at least not officially) the people were mostly Christian and not as "alien" as other Easteners. (Or as "alien" as Westerners are to Asians.)
Just look back to WWII and look at the propganda in the US. It was much easier to make enemies of the Japanese than the Germans or Italians. Why did we intern the Japanese and not the German or Italian Americans? Of course Pearl Harbor, but race surely came into play as well. And, look at the race hatred and fear of the Americans on the Japanese side of things.
Just something to consider...
Steve