Just because of their severe numbers advantages, it would have to be either India or China. However, I'd say India without a doubt.
Here's why. Suppose you're from some tiny country that has no chance to win any of this. You'd want to at least have some impact on the final winner, so you'd probably attack countries that you don't like rather than random ones, just so that at least if you die, you'll have taken out some of those evil guys from Hated Country X. This means that North Korea would probably be the first country to fall (they probably would've been anyway), and Israel and the Balkans would probably go pretty early as well.
So, it basically all would come down to which one of the juggernaut countries is the most globally liked. Lots of people hate China for reasons better not discussed here. Thus, India wins.
If you're looking for a sleeper, try Indonesia. They've got a ton of people, and nobody really hates them (at least not as far as I know).