How Questions Over a Spy Balloon and U.F.O.s Fed a Crisis Between the U.S. and China

Other murky actions have challenged U.S. analysts trying to read Chinese intentions. On Jan. 28, when the balloon approached the Aleutian Islands and American airspace over Alaska in its off-course trajectory, the balloon’s self-destruct function did not activate, U.S. officials said. Chinese operators may not have wanted to destroy the balloon; it is also possible that they attempted to trigger the self-destruct mechanism and it failed.

Operators or officials might have mistimed the winds and thought currents would carry the balloon quickly over Alaska and out of American airspace to the Arctic Ocean. Or they might have decided to allow the balloon to continue onward to see what kinds of intelligence it could collect — not foreseeing the diplomatic and political maelstrom that would ensue once the balloon drifted with the winds to the continental United States.

Some American officials say they know the intended trajectory of the spy balloon in part because the U.S. government tracked the balloon from the time of its launch in late January from Hainan Island in southern China, a detail first reported Monday by The New York Times, and observed it as it moved across the Pacific. U.S. agencies also monitored the balloon as it was pushed in different directions by the winds, officials said.

Once the balloon went off course, as U.S. officials suspect, Chinese officials and the machine’s operators, who could be employees of a civilian-run balloon maker under contract with the People’s Liberation Army of China, appeared to make a series of bad decisions.

Chinese operators and officials did not take any immediate action after the two top American diplomats, Antony J. Blinken, the secretary of state, and Wendy Sherman, the deputy secretary, issued a formal démarche to a senior Chinese diplomat, Zhu Haiquan, at the State Department around 6:30 p.m. on Feb. 1 over the balloon, telling him his government had to do something about it. Mr. Zhu appeared taken by surprise, U.S. officials said.

More than 24 hours later, and a half-day after the Pentagon announced the existence of the balloon, Chinese foreign ministry officials in Beijing spoke privately to diplomats in the U.S. Embassy to tell them the balloon was a harmless civilian machine that had gone off course.

Later that Friday, Feb 3., after China issued a public statement expressing regret, and after Mr. Blinken canceled a planned weekend visit to Beijing, the balloon appeared to accelerate, U.S. officials said.