Chinese Su27 wikipedia commons China crossed the middle line that marks its border with Taiwan June 29 to repel a U.S. spy aircraft (via Zero Hedge).

This is the first time in more than a decade Chinese and American aircraft had come into contact. The last time -- a Chinese fighter collided with a U.S. reconnaissance aircraft -- created an international crisis when the crew was held by the Chinese for days.

According to the Financial Times, Taiwan's defense ministry confirmed that two Chinese Su-27 fighters crossed the middle line, adding "the incident was not a provocation".

“This was not between Taiwan and China, but between China and the US,” said a senior Taiwanese defence official. “The Chinese crossed the line to repel a perceived intrusion by a US reconnaissance aircraft.”

A Chinese defence source said: “This once again shows that US military activity very close to our territory is a destabilising factor in the region.” The incident in the Taiwan Strait comes as the US and China are trying hard not to let rising tensions in the South China Sea derail a recent improvement in bilateral military relations.

Taiwan and China have long respected the middle line drawn up in a mutual defense treaty in 1954.

