NATO's new out-of-area policy could be seen as a mandate to police the entire Eurasian landmass.
The NATO attack on Serbia bypassed the UN to attack a sovereign country. China wants everything to go through the UN Security Council (where it has a veto) and strongly believes in the sovereignty of nations to handle their own internal affairs any way they want without complaints about human rights.
The new US-Japan defense treaty apparently covers Taiwan, bringing Tokyo into Chinese affairs where Beijing feels it has no business.
Japan's decision to build a missile defense system (supposedly to protect it from North Korea) would reduce China's ability to blackmail Japan.
Taiwan's decision to build an anti-missile defense system makes a Chinese attack less likely to succeed.
South Korea may seek inclusion in the US-backed missile defense system, reducing the ability of China's client state, North Korea, to threaten it.
Taiwan's sharp moves away from "one China" under President Lee.
Washington has tilted away from (pro-China) Pakistan and towards (pro-Russia) India.
The espionage and fund-raising scandals in Washington have had little effect on President Clinton but have wiped out a decade of Chinese political progress. Chances of getting US agreement for China to enter the World Trade Organization as a "developing" nation are now effectively zero.--Stephen V Cole
A wide range of developments is feeding China's perennial fear that it is the target of a long-term American plot. Some of these developments include: