It could do, yes.
I suppose it depends on exactly how the Chinese bubble bursts. Outside of Beijing, organised crime has a lot of power, and there is a school of thought, popular among modern day criminologists and some IR theorists (I include myself in that, despite not actually having a theory yet) that the state is essentially organised crime, codified and writ large. Protection rackets, private militias and local detachments of the PLA may be able to keep order where the central government cannot. While this would definitely put a dampener on Chinese military spending, defensive weapons are a lot cheaper than offensive ones, and Chinese doctrine emphasizes asymmetric, unconventional attacks, and low-tech weapons designed to undercut more advanced American systems (look up the "Assassin's mace) sometime.
Either way, China still spends much less than America on its military, so I doubt this would make much of a difference on a military level.
However, the economic level is the worry, and you're right to be concerned there. As I understand it, China welcomed American investment to make consumer items to sell to America, and buying up enough debt and dollars to keep the US afloat, so it could continue to keep buying Chinese made goods. However, increasingly, China is cutting America out of the picture and selling to its enriched population. America and China have also had a tense trading relationship for about a year and a half now. There could be a move towards protectionism in both countries, and while decreasing trade is linked to war, the more immediate worry is the economic impact.
That will create a populist backlash, and since in modern day America populism is exclusively rightwing, that means a climate friendly to Teabaggers and the GOP. I'm pretty convinced that in 2012 or 2016, whenever the Republicans win, there will be war with Iran, as a final military "stimulus" to jump start the economy, regardless of what actual reasons they give. However, even if China does collapse or somehow become less powerful due to internal tensions, there are other nations willing to take advantage of that. Namely, India and Russia. The Russians are smart, very smart. Their leadership is mostly made up of ex-KGB men who went on to make fortunes in the new capitalist Russia, so they're mostly pragmatists, not ideologues. They also think in terms of geostrategy. Russia's still a declining power in the long term, but in the short term, their army is in much better shape than at any time in history and they're sitting on 3,300 nukes. Their weapons systems are also in high demand in the Middle East and Africa, giving them a fairly steady income. Not to mention their use of energy resources.
Russia is also fairly chummy with Germany. Putin's plan from 1999-2004 was to use a European-Russian alliance to reign in American unilateralism. He pretty much abandoned that after Beslan though, due to some of the circumstances around that attack (Chechen terrorism is affiliated with some very pro-American and European groups). But the friendship with Germany remains, and with Europe needing energy from any quarter willing to sell, the Russians might start playing their old trick of "lowering oil prices for friends".
OK, that got a little off course, but hopefully I answered the main questions.
