I base this on several factors one being the type of governments in the US and China. In the case of the US we the people have the ability to influence/control our government’s actions and that is undeniably and critically absent in the Chinese political system.
Also based on our countries values the US government is more committed to humanitarian aid and human rights issues (not saying we don't have our errors) While China is undoubtedly a repressive regime. So why would we think the Chinese would treat citizens of the world any better than they treat their citizens and why would we think this would change with China becoming a superpower?
Although you would be correct to state both the US and China has armed unstable regimes I think there is a difference of degrees.
Take Iraq as a case in point. We armed Sadaam Hussein to be a balance in the region to Iran. After Sadaam proved his instability by invading Kuwait(08-02-90)the US took measures to limit his power.
However China in Sep of 1990, after the Iraq invasion of Kuwait provided Iraq with lithium hydride a chemical useful in both boosted fission and hydrogen bombs.
China provided Pakistan with bomb designs, enriched uranium, & tritium (used to trigger hydrogen bombs) it even tested a bomb for Pakistan. China was Pakistan’s primary source of nuclear related equipment and technology and we now know A.Q. Khan (from Pakistan) sold his nuclear know how to North Korea, Iran, Libya etc.
China has provided ballistic missile (M-9) technology to Syria.
China constructed a plutonium production reactor in Algeria.
As to the monitoring of citizens even with our new big brother NSA phone tapping, even with the proliferation of technology including web cams and GPS locating devices we are nowhere near the repression and monitoring of Chinese citizens.
China is an authoritarian government determined to control information. Case in point the Internet discussion we just had about yahoo giving the Chinese personal information about one of its users, a journalist now serving 10 years in prison for leaking state secrets. Yahoo is also investigating a second case in which it allegedly did the same thing. At the end of 2004, China had forty-two journalists in prison.
I believe the majority of monitoring is through the CCP and its members. One example (not sure if it’s still the case) but in China you had to get permission from your boss to get married.
So while you may hate that camera that takes a photo of you going through the red light… there is no comparison with regard to degree of monitoring and repression as a result of that monitoring.