There are Americans, and other people in the world, who are fearful of a growing China. No question. Some of that is economic rivalry... let's be clear about that. But I don't think enough people in China see the political part too -- and the Chinese government prevents its citizens from seeing many of the huge political negatives that the Chinese leadership has been guilty of.
For many Chinese, the economic prosperity has been a great boon -- so it's easy to put a blind eye to these great political negatives. It's easy to look the other way and think your boss is a great guy when the raises keep coming. But if your boss is a mobster, breaking legs of this group and that, and burying this dissenter and that in cement, and not sharing that with you for obvious reasons, many Chinese will have a very hard time seeing that boss in a negative light until they are directly hurt buy him. I cannot blame the many Chinese who are benefiting from this mob boss for thinking he's a great guy and not being critical enough of the negatives -- I might be the same way if in the same position. But a mob boss is a mob boss, and evil is evil.
For example, I've been in Delhi, India for the past couple of weeks, and it's clear that the Indians don't trust the Chinese government one bit. In fact, if you read the newspapers, India is clearly in a cold war with China, as there are reports of Chinese developing nuclear submarine bases that ring around India in the news all time time. In my time in China, none of this has ever been discussed. The media in China never reports it. And while some people in China will complain about their government for this and that (particularly the older generations, less the younger generations), it's only done in private -- in closed cars on the street with foreigners they can trust, for example. Many Chinese I've met have expressed fear that they could never make these kinds of complaints around their neighbors or friends even, because they would be turned in by their neighbors for saying something negative and bad things would happen to them and their family. This is not good. This is an oppressive regime on the level of Stalinist Russia, no question.
I have zero belief that China would be better than the U.S. is today as a political power. (And here you must understand that I find virtually all of the U.S.'s behavior on an international scale of the past 7 years entirely reprehensible -- and doing the opposite of what it should do at every opportunity. I do not sugar-coat my own idiotic country's flaws -- but unlike someone in China, I can say so to my coworker without fear of being imprisoned.) Heck, you cannot even buy Chinese toothpaste or dog food around the world without the risk of death.
Just my experiences in India recently have proven this. China has been completely lax at even addressing North Korea properly in its own backyard, though I am encouraged that perhaps at least the watchful eye of the Olympics has made the Chinese government respond well the the tragedy unfolding in Sichuan. This is very different than, say, their typical mode of behavior in denying that SARS exists and that they have everything under control and there is no problem while a virus spreads and kills people. And if you combine the Chinese government's mentality when it comes to Tibet and Taiwan, it's very much outdated and territorial like Europe around World War I -- a mentality that has lead to millions of dead over outdated reasons that really don't matter much. China seems in no way capable today of avoiding the mistakes of Europe in the early 20th century on a territorial/military basis.