Social work alone can’t defeat AQ, either.
Some estimates have the Chinese economy overtaking that of the US before 2020 (of course, those were all made before the global economy started headng towards a death spiral, so they may well be off), and if you don’t think that building up conventional weapons wasn’t an intigral part of the strategy used by both sides during the Cold War, you’re sorely mistaken.
Germany and Japan never invaded the US (well, not in significant numbers, at any rate), by your logic they were never a threat to the US. HIstory would disagree with your assessment, then. Taiwan is a close ally of the US, and were China to invade them, we’d quite possibly go to war over the matter. The battle would not be fought on US soil (just like WWI and WWII wags not fought on US soil). Suppose the US or China decide that the other side shouldn’t have access to the oil in the Mid-East, you think a lot of the fighting is going to be concentrated here? Of course not (though if the Chinese have some long range bombers, we could well get hit, assuming a “best case” scenerio and the war doesn’t go nuclear), we’ll fight it in the Mid-East, and bomb China (and possibly attempt to occupy key points of Chinese territory). The standard rule of thumb for military engagements is that you need at least a 3:1 ratio of your forces to those of the enemy to assure victory, for the US to be able to do that is going to require a much larger military.
“Conceivable”? Its already a reality. We’re involved in two of them at the moment, in case you hadn’t noticed, and the reason they’re both going on has a great deal to with the fact that we didn’t commit the level of military forces necessary to accomplish the job. Yes, yes, I know, I know, there’s a number of non-military things that we should have done as well (like staying out of Iraq), but the fact remains that we should have put more forces in the field than we did. Nor is it like we’ve got much reserve capacity when it comes to the military, at the moment. Our forces are straining to the breaking point, not only in terms of personnel, but also in terms of equipment, what happens if we have to deal with another “brushfire” in another part of the world? You think that peace, love,and understanding will break out in Iraq and Afghanistan? We don’t necessarily need to have forces in those countries at this point to ensure that AQ doesn’t come to power, but we’d damned well better be able to put forces back into those countries if things turn to shit after we leave (and in Afghanistan, at least, AQ might decide that because the US is tied up elsewhere, it would be a good time for them to try and retake the country).