Imagine that you live in China, and that the only news you get comes from state-controlled media. In early December 2019, you begin to see stories about a mysterious new virus, not unlike pneumonia, affecting patients at hospitals in Wuhan, a central city of 11 million people. Day by day through January, the number of reported cases multiplies, and in February, local officials order you to stay at home. It's inconvenient, but authorities seem to have the situation under control. "Despite coronavirus outbreak, China will continue to advance," the state newswire Xinhua reports on February 7.

Now imagine you're active on Chinese social media. In mid-January, doctors in Wuhan start sounding the alarm—the virus is overwhelming hospitals, and the authorities seem ill-prepared to contain it. Government censors, citing a concern over the spread of "rumors," shift into high gear. Unnerving posts pop up and then quickly vanish. One Wuhan doctor, Li Wenliang, issues a dire warning, and the government detains him for rumormongering. He falls ill with the virus and dies on February 7, just as state media is trumpeting the country's effective response. Li's last words are: "a healthy society shouldn't have only one voice." Social media explodes with a degree of outrage that even China's censors struggle to contain.

The Chinese government is widely seen as having finally gotten the crisis under control. Last week, Beijing reported that the number of new confirmed cases of COVID-19 had dropped to zero. (On Sunday, Beijing reported 46 new cases, 45 of them reportedly imported from overseas.) Quarantine measures are easing, even in Wuhan. Beijing is leading an international fight to contain and treat the illness, donating medical supplies and diagnostic tests to countries around the world. At home, it is implementing sweeping policies to aid economic recovery. And the authorities have formally exonerated Dr. Li.

Yet Beijing's well-documented record of coverups, censorship, and intimidation of critics should give us pause about accepting its narrative. It's now well-established that Chinese authorities covered up the spread of the disease in its early stages. Beijing initially refused to allow U.S. disease experts to visit Wuhan. As the virus gathered pace, it censored even tangential discussion of the crisis online. It detained hundreds of citizens, including medical workers, for "spreading rumors" or criticizing the government's response.

So are Beijing's current data accurate? Has China really stemmed the tide? "It would be really hard to speculate on this question because nobody really has any evidence whether the Chinese government is being honest or not," says Minxin Pei, a China specialist at Claremont McKenna College.

One complicating factor is the pandemic's sheer unpredictability. New information emerges on a daily basis from scores of countries, and conflicting data abound. We remain unclear about the virus' virulence, its degree of contagion, and its incubation period, which could range from less than two weeks to 24 days. Estimates of its mortality rate range from less than 1 percent to nearly 6 percent."The data collected so far on how many people are infected and how the epidemic is evolving are utterly unreliable," writes the Stanford disease prevention expert John P.A. Ioannidis.

China, as the source of the outbreak, clearly possesses troves of potentially useful information. In assessing the reliability of that information, it is important to distinguish Beijing's incentives to be transparent about its current circumstances from its incentives to be transparent about its decisions when the outbreak began.

Beijing has ample reason to be honest about its current data. The Chinese government is obsessive about its global image, and if attempts at a current coverup are revealed—especially amid their humanitarian aid campaigns abroad—their growing clout would quickly evaporate. Beijing knows the risks of a well-timed leak. (Despite its draconian information controls, it cannot control everything, as Dr. Li's protest aptly demonstrated.) We also know that China is adept at disaster control. Its authoritarian governance structure allows it to mobilize resources quickly, and to control communities with astonishing precision. When Beijing says its citizens are under strict quarantine, we have every reason to believe it.

Yet those incentives could abruptly change. Despite state media's united front of reassuring headlines, the country's situation remains volatile. Beijing's count of "confirmed cases" excludes asymptomatic carriers, according to a COVID-19 "prevention and containment plan" published by China's National Health Commission. The Chinese magazine Caixin reported provincial data on March 1 that suggested as many as one in six carriers could be asymptomatic, and their risk of spreading the virus remains unclear. Schools in Beijing are still closed, and many of the city's residents require special authorization to leave their residential complexes. Wuhan is still under near-complete lockdown. Local and regional officials are under immense pressure to report low numbers of new infections. The country risks being overwhelmed by a second wave of cases, upsetting the government's narrative and incentivizing officials toward dishonesty.

That brings us to the past. Any true accounting of this pandemic, and of humanity's efforts to contain it, will require close scrutiny of what transpired in Wuhan from December 2019 through February 2020. Yet Beijing is desperate to avoid being seen as the incubator of a global pandemic, and its accounting of that period is complicated by rampant censorship, intimidation, and deflection, leaving little room for trust.

Chinese authorities have exerted strict control over the internet since the network first entered the country in 1994. But under President Xi Jinping, who rose to power in 2012, angering authorities on the web often carries severe, real-world consequences, including police visits, extended interrogations, forced confessions, and lengthy stints in jail.

As of March 12, at least 452 internet users in China have been "punished" for "spreading rumors" related to the coronavirus, according to the nonprofit group Chinese Human Rights Defenders. People have reportedly been arrested over even benign or equivocal statements that are now impossible to corroborate, including accounts of suspected cases at small city hospitals. At least three citizen journalists have gone missing since the outbreak began; they had traveled to Wuhan, where they reported that local authorities were underestimating and downplaying the crisis. Some officials weren't implementing disinfectant measures, they reported; in some areas, food supplies were running low.

On March 15, 69 year-old Chinese tycoon Ren Zhiqiang—a longstanding critic of the Communist Party—went missing after he posted an article denouncing the government's response to the outbreak. "Without a media representing the interests of the people by publishing the actual facts, the people's lives are being ravaged by both the virus and the major illness of the system," he wrote. On March 17, Beijing expelled all China-based reporters from The New York Times, The Wall Street Journal, and The Washington Post. This was at least ostensibly a retaliation against the Trump administration's restrictions on U.S.-based Chinese reporters, but the move sends a clear message that independent reporting within China's borders can carry steep costs.

This has provided fertile ground for conspiracy theories, many of them spread by Chinese officials—and many of them, especially in recent weeks, suggesting that the pandemic did not originate in China. In mid-March, Chinese Ministry of Foreign Affairs spokesman Zhao Lijian claimed that COVID-19 is an American disease spread by the U.S. Army during an autumn visit to Wuhan for the 2019 Military World Games. A Sunday editorial in the state-run Global Times implored scientists to "figure out where the virus started."

The Chinese government's role in the pandemic—both in containing it and in allowing it to spread—will be debated for years. But in a time of so many unknowns, one thing is abundantly clear: Any information coming from China should be treated with caution. The authorities there have not earned anyone's trust.