[SCAJolly]

Seeing as America didn't tolerate to have to share the world with the USSR, America will still not tolerate to have to share the world with China. Developing econimically and militarily in ways no one anticipated, China is truly a competitor for the title of The World's Largest Superpower.
Not only are they developing a blue-water fleet that in not many decades will rival that of the US, but they are also drooling over "re-uniting" Taiwan with its motherland, and this latter is of great concern to USA and Japan. America has already taken the side of Taiwan, and should a Chinese strike be launched, she has little to do but join in the melee. Officially, of course, there is much else to do, but if an invasion is launched, then by God there aren't many alternatives left. I doubt any US president is willing to tolerate to lose face in such a battle.
Also, the Chinese will perhaps not be as careful with their nuclear weapons as the Soviets and westerns were. They share many of the basic understandings of moral and ideology, while China's (the men in charge, of course) perception of the world is a completely different one.