In light of several posts that I wrote addressing Chinese power, their potential to stumble, and the reaction of the neighborhood, Strategytalk has a good overview of China and the region.
They make a good point that China really doesn't want war and would rather trade (although stealing technology is part of "trade" and not "war" in their thinking). That is a positive when you consider that Hitler wanted war. He thought it was good for the people to have a struggle. So that Chinese preference isn't nothing.
But it isn't everything, either.
One, is it war when you are subduing what you think is a rebellious province? War, properly speaking, is between states. China does not consider Taiwan a state. Yet regardless of the legalities it would look a lot like war.
Two, as China's military grows, the military option for any problem obviously grows and the chance for war increases. If 9/11 had happened to France, despite their mostly decent military, the option of overthrowing the Taliban government, chasing al Qaeda into the hills of Pakistan, defeating the Taliban in their southern stronghold, and eventually killing Osama bin Laden with a surprise special forces raid would have been out of the question for France. Britain, I think, could have done the first and second steps, but not the third. And without the third, they couldn't have gotten to that fourth step even though they could have pulled off something similar (but without the high tech helicopters).
Third, leaders make stupid decision all the time. China could believe a quick blow can rapidly resolve a problem and find they have an open-ended war instead. And if the target is Taiwan--believed in Peking to be a purely internal matter--and America or Japan intervenes, it would become a war in legal terms, too. The same could apply to Tibet if there is an uprising and India gets involved, leading to a China-India war.
Fourth, even a country that doesn't want war can go to war. China intervened against us in Korea and Vietnam and in the former, it led to war between us. It could have happened in the latter. And China went to war with India and Vietnam. There were also some pretty hefty border clashes with the Soviets. And minor clashes in the South China Sea where China took some islands.
And fifth, accidents happen or escalation from a minor clash could spark a war.
And don't speak to me about Chinese weaknesses as if that is the last word. I perfectly agree that America is far more powerful economically (I don't know why so many Americans believe China's economy is bigger than ours) and our military is far more powerful than China's. Just the fact that the debate is how we can operate close to China and not the reverse should make that clear. We are a global power and China is not--and may never be considering all the foes they have surrounding them. If, because of any of the objections I cite above China goes to war, China has the advantage of location. We will have the power to counter-attack successfully, but that will require a political decision to mass that power and take the risk of going hammer and tongs with a nuclear power (however weak they are in that regard).
Oh, and given the above and related to the fifth reason war could happen despite China's preference for trade, remember that some damn fool thing in the Balkans unrelated to Germany led to a German crisis with Russia, which led Germany to attack France because Germany knew that time was not on their side. Germany believed that they had to use their speed of mobilization to defeat France before the slower Russia could mobilize. Attacking Russia risked having France decide to jump in to get their lost provinces back from Germany while Russia was fighting in the east.
Today, China knows that because of their location they can gain an advantage over America's relatively sparse forward-deployed forces in the western Pacific. But that advantage will erode if we have time to mobilize our resources. The same pressure to act aggressively will play on Chinese nerves in a crisis as they watch our distant forces gather and prepare to move west. And what if Chinese political leaders--who may very well sincerely and resolutely prefer trade to war--aren't the people who decide if there will be war?
And as long as I am on a roll of worst-case scenarios, what if something happens that completely upsets the variables in China's calculation that it prefers trade and prosperity to the potential failures of war? What if their economy tanks? Doesn't that make the trade prosperity issue less compelling? Especially if the peasants are revolting? Especially if the xenophobia the Chinese rulers have been stirring up to replace faith in communism leads to public pressure to deal with whatever foreign devil is "causing" their economic problem?
There is a lot of military power in east Asia. Asia spends more on military power than Europe, now. Sheer density of militarily capable states increases the chance of stuff happening that can spark a war.
I'm just not comforted by the notion that war can't happen because it doesn't make sense and nobody wants it. Stuff happens. We have lots of books to show that.