Did Covid jump from an animal to a person at a food market in Wuhan, China — or leak from a research lab there? That question remains the pandemic’s central mystery.

There may never be a definitive answer. But scientists and other experts continue to study the issue and uncover relevant information. This week, The Times Magazine published a story about Covid’s origins by David Quammen, a veteran science journalist, and I’m turning over the rest of today’s newsletter to Julian Barnes, who covers intelligence agencies in Washington. — David Leonhardt

In the early days of the pandemic, I was speaking to a variety of U.S. intelligence officials who believed that China was hiding the truth of what happened with Covid. They were right: China was.

In the name of safety, Chinese officials ordered that coronavirus samples be destroyed. At best, this hampered the later investigation into Covid’s origins, and at worst it was a sign of a cover-up.

In this context, some of those intelligence officials believed that people were not paying enough attention to the lab-leak theory. They spoke about a history of accidents and safety problems in Chinese labs. Some, including the lab in Wuhan, also had a history of “gain of function” research, which tries to create dangerous viruses so scientists can learn how to combat them before they emerge in the wild.

The problem is that viruses can leak from labs with destructive effects. The 2001 anthrax attacks leaked (purposely) from Fort Detrick, one of the most secure labs in America, and a deadly 1977 flu outbreak likely came from a Soviet lab. (Josh Clark’s “The End of the World” podcast did an episode on near-miss lab leaks.)

These patterns probably helped explain the conclusion that F.B.I. intelligence officials made, with medium confidence, that a lab leak was the most plausible origin of Covid. The Department of Energy also considers the lab-leak theory to be the more likely explanation, at least in part because of the safety protocols in the Chinese labs.

At the end of the Trump administration, the State Department released a piece of intelligence that seemed to bolster the lab-leak hypothesis: In late 2019, a few researchers at the Wuhan lab, known as the Wuhan Institute of Virology, became ill with flulike symptoms.

From the beginning, there were divisions in the U.S. intelligence community. The politics swirling around lab-leak idea made intelligence officers wary of reaching conclusions, for fear of being seen as partisan. Some Republicans had gravitated to the theory, and President Trump pushed it as a way to blame China for Covid. Some Democrats dismissed it as a conspiracy theory with xenophobic overtones.

Still, the lab-leak theory gained traction early in the Biden administration because of the sick Wuhan workers and China’s failure to cooperate with international investigators.

But the situation has changed somewhat over the past year.

One development: U.S. intelligence agencies determined that the sick lab workers in Wuhan might not have had Covid. As a recent report explained, “The researchers’ symptoms could have been caused by a number of diseases and some of the symptoms were not consistent with Covid-19.” That report — which is short and easy to read — is nominally neutral. But because it undermined some evidence that the lab-leak advocates had cited, the report had the effect of bolstering the case for natural transmission.

The intelligence community also says there is no evidence that the coronavirus research at the Wuhan lab could have been a precursor to the virus that causes Covid (as the Times Magazine story details).

This information helps explain why five intelligence agencies lean toward the natural-transmission theory. While officials have not explicitly outlined the reasoning, the scientific research tracking the virus’s origins seems to favor natural transmission.

The C.I.A., the nation’s premier spy agency, does not lean one way or the other. Officials say that is because too much evidence has been lost — because of the chaos of the pandemic, China’s destruction of samples and the passage of time.

U.S. intelligence agencies work by stealing secrets from other countries. But American officials said that China did not appear to want to know what caused the pandemic. Some Chinese officials believe the case for natural transmission. Others are less convinced but know that if evidence points to a lab leak, it will be bad for their country. So they have every incentive not to look. If you want to keep a secret, as George Orwell wrote, you must hide it from yourself.

We have to be prepared that we might never know the answer.

Related: “Some contrarians say that it doesn’t matter, the source of the virus. What matters, they say, is how we cope with the catastrophe it has brought, the illness and death it continues to cause,” David Quammen writes in the magazine. “Those contrarians are wrong. It does matter.”

Politics

Business

  • UPS reached a tentative deal with unionized workers, likely averting a strike next week.

  • The I.M.F. is growing more optimistic about the world economy: It expects inflation to ease and growth to increase this year.

  • The Federal Reserve is expected to raise interest rates by another quarter of a percentage point today.

War in Ukraine

Other Big Stories

  • China removed its foreign minister, a former protégé of Xi Jinping’s who vanished from public last month.

  • Cambodia’s prime minister, Hun Sen, one of the world’s longest-serving leaders, said he would resign and hand power to his son.

  • A New York gynecologist convicted of luring women across state lines and abusing them was sentenced to 20 years in prison.

  • A federal judge wiped out the conviction of Bowe Bergdahl, the former Army sergeant held captive for five years by the Taliban, citing potential bias by the military judge in the case.

  • Soaring rent is pushing people in Orlando, Fla., onto the streets and into dangerous heat.

Opinions

South Koreans are taught to long for reunification with the North, but differences in culture and ideology and potentially high economic costs for the South stand in the way, Haeryun Kang writes.

Here are columns by Paul Krugman on Japan’s lessons for China’s economy, and Bret Stephens on Israel.

Human canvases: Artists’ subjects traded clothes for body paint.

Listen: Can you speak bird? Take our quiz.

Out of view: Melania Trump wants what she couldn’t get at the White House — privacy.

Lives Lived: Johnny Lujack, who won the 1947 Heisman Trophy and played on three national championship teams, was Notre Dame’s most publicized football player since the 1920s. He died at 98.

Japan dispatched Costa Rica, 2-0, a second strong win that’s prompted chatter about title hopes.

The U.S. midfielder Rose Lavelle, a standout during the last World Cup, said she’s ready to play tonight against the Netherlands as she recovers from a knee injury.

The scrappiest, most resilient underdog team is Haiti, Kurt Streeter writes.

Stopped heart: Bronny James, the son of LeBron James, suffered a cardiac arrest during practice at U.S.C. He is in stable condition.

A cold reality: The Bills could cut Damar Hamlin after training camp, months after he went into cardiac arrest during a “Monday Night Football” game. (Such episodes remain rare.)

Federal case: Joe Lewis, the 86-year-old British billionaire who owns the Tottenham Hotspur soccer club, was indicted in New York on charges of insider trading.

Saving tourist dollars: If you’ve spent time on TikTok, you might recognize Monica Poli’s voice, yelling in Italian: “Attenzione, pickpocket!” Poli and other citizens roam Venice shouting at people they believe to be thieves preying on tourists. After decades of patrolling, she began to post her vigilantism on TikTok and became a sensation.

“We want the tourists, people coming to Venice and Milan, to pay attention,” she told The Times. “The pickpockets are so quick.”