American officials said they began having talks with airlines on Wednesday and characterized the guidance Friday as simply following established international air protocols independent of any political deliberations. The American announcement came on the same day that Chinese state news media said that China sent jets aloft and that they identified two American surveillance planes and 10 Japanese aircraft in the air defense zone the country declared last weekend.

Although there was no indication that China’s air force showed any hostile intent, the move raised tensions. The Chinese had also sent jets on patrol into the contested airspace the day before, but Xinhua, the state-run news agency, indicated that the planes on Friday were scrambled specifically to respond to foreign jets in the area.

Image Credit... The New York Times

Earlier in the week, the United States sent unarmed B-52s into the area, and they proceeded unimpeded. China then appeared to back down somewhat from its initial declaration that planes must file advance flight plans or face possible military action.

The administration’s decision on Friday underscored the delicate position President Obama finds himself in, drawn into a geopolitical dispute that will test how far he is willing to go to contain China’s rising regional ambitions.

China’s move thrust the United States into the middle of the already prickly territorial clash between Beijing and Tokyo, a position the administration had avoided for months even while reiterating that the mutual defense treaty with Japan covers the islands. After the Chinese declaration last weekend, American officials feared that, if left unchallenged, the Chinese action would lead to ever greater claims elsewhere in the Pacific region.

But with planes flying so fast and in such proximity, the administration’s worries grew that an accident or an unintended confrontation could spiral out of control. A midair collision between a Chinese fighter jet and an American spy plane off the coast of China in 2001 killed the fighter pilot and forced the spy plane to make an emergency landing on Hainan Island, setting off a diplomatic episode until Beijing released the American crew and sent the plane back, broken into parts.