The Chinese apparently are not to happy about the recent arms sales to Taiwan:

China suspended military exchanges with the United States and threatened sanctions against American defense companies Saturday, just hours after Washington announced $6.4 billion in planned arms sales to Taiwan.

The development has further strained the complex relations between the two powers, which are increasingly linked by security and economic issues.

China’s Defense Ministry said the sales to self-governing Taiwan, which the mainland claims as its own, cause “severe harm” to overall U.S.-China cooperation, the state-run Xinhua News Agency reported. The Foreign Ministry threatened sanctions against U.S. companies involved in the arms sales.

A spokeswoman for the U.S. Embassy, Susan Stevenson, had no comment on China’s actions Saturday.

Taiwan is the most sensitive topic in U.S.-China relations, and the sales announced Friday could complicate cooperation between the two sides on issues ranging from Iran’s nuclear program to the loosening of Internet controls, including a Google-China standoff over censorship.

China’s Vice Foreign Minister He Yafei warned U.S. Ambassador Jon Huntsman that the sales of Black Hawk helicopters, Patriot Advanced Capability-3 missiles and other weapons to Taiwan would “cause consequences that both sides are unwilling to see,” a ministry statement said Saturday.

The United States is Taiwan’s most important ally and largest arms supplier, and it’s bound by law to ensure the island is able to respond to Chinese threats.  [Associated Press]

This is really nothing to get to concerned about because this is what the Chinese government usually does in response to arms sales to Taiwan.