Well, I can easily see Israel fighting a war with the Arab powers, but I can't see that turning into a "world war." I can also see us fighting Al Qaeda (we already are), but that's not a world war in the traditional sense of the term. A war with Germany is not going to happen any time in the next century. Out of your options, that leaves open the possibility of war with an "Asian nuclear power." I can see us fighting a war against North Korea, who I guess qualify as a nuclear power, but that can hardly be considered a world war.
The closest we're going to get, I think, is with China. But I don't really see us fighting a major war against them either. With both countries in the hand of comparatively rational leadership, the mutually assured destruction brought upon by nuclear weapons should keep most armed conflict in check. We might see another cold war or a funding of enemies (possibly including terrorists), but I don't think a full scale war against China is in our future. That doesn't mean that it's totally out of the question or that we shouldn't be prepared, but it doesn't sound very likely to me.
I also wonder whether a United States war against China could really be called a world war. The two world wars of the twentieth century were called "world wars" not just because they were huge and destroyed entire regions, but because they proliferated around the world. Unless China can bring together a credible axis of allies somewhere other than their immediate vacinity, the war against China will remain a largely local conflict. Other nations may enter on our side, but that wouldn't be any more of a world war than the first Gulf War was.
China will go to war with India, the US does the smart thing and stays out of it.
I think this is a much more real possibility. China knows that they can't win a war against us, but that won't stop them from picking a fight to gain regional power.