I know you didn't ask me, but I'll answer anyway.
There is no way to really know when a country will overtake another in military ability, or by many other measures. That depends on too many factors, and unless its an obvious relatively short run thing (like the ability of the US navy to grow to the point where it could sweep the Imperial Japanese Navy away) it probably can't be predicted reliably.
A related question, when might they possibly be able to overtake us is still hard, but answerable. It will be quite some time. As long as the US tries to be the preeminent power in the world, it will be at least several decades, likely not in my lifetime. Their economy is still noticeably smaller than ours (and has to maintain over a billion people), and also it takes time to develop and build modern weapons, to train large numbers of people, to develop technology, techniques, skills, and effective military traditions.
But China doesn't have to equal the US across the world, to be a threat. Its nuclear weapons are a threat (deterred by ours of course but still a threat), and it could develop the ability to take Taiwan or intervene in other near by locations to a far greater extent than it can now. And if it doesn't want to wage war itself (a prudent decision even if it was more powerful) it can give or sell weapons to others who cause problems for us. |
