[cglace]

If we were going by the original definitions of first world, second world third world. China would be a second world country since it was aligned with Russia and not the US.

[billforsternz]

Not really, the Russians and Chinese were both communist but were rivals rather than allies through most of the cold war.

[gaius]

There was no first and second, it's third world as in "third person". NATO, Warsaw Pact, everyone else.

[speleding]

Yes, there was a first and second world, it used to denote then Nato and USSR block respectively, that's how the third world got its name. See http://en.wikipedia.org/wiki/Second_World