By Tim Culpan

You can’t get much more American than Disney. So it was quite a coup when a Chinese upstart managed to snag one of the family entertainment giant’s senior executives.

Kevin Mayer was head of Walt Disney‘s streaming business before Beijing-based ByteDance tapped him to become chief executive officer of TikTok, the company’s short-video service for international markets. Less than four months later, he’s now gone from ByteDance, whose $140 billion valuation makes it the world’s biggest unicorn.

Beyond losing a CEO, Mayer’s departure bruises TikTok’s makeover into an American company that’s not beholden to the Chinese government. President Donald Trump alleges that it’s a national security threat because of close links to Beijing and access to data on U.S. users. He’s issued an executive order that essentially forces a sale to a non-Chinese buyer.

As my colleague Tara Lachapelle wrote when Mayer was appointed in May, he’d been considered a front-runner to lead the Magic Kingdom upon Bob Iger’s departure before the job went to Bob Chapek. Being passed over may have been a reason for Mayer to jump ship. Or it could have been the prospect of a lucrative package at a fast-growing company. Perhaps he simply wanted to lead an exciting new business on the cutting edge of entertainment and technology.

Whatever Mayer’s motives, one thing is certain: A key reason for ByteDance to hire him was to put an American face on a Chinese company trying to shed its roots and become a U.S. entity divorced from even the perception of any ties to Beijing. Indeed, in suing the U.S. government this week, TikTok offered the nationality of its senior management as proof of its U.S. credentials.

The key personnel responsible for TikTok, including its CEO, Global Chief Security Officer, and General Counsel, are all Americans based in the United States—and therefore are not subject to Chinese law.

Mayer may have been a little naive. At the time of his appointment, Washington had already launched a national security review of the TikTok app, which curates user-generated short videos and has over 100 million U.S. subscribers. The Federal Trade Commission had fined ByteDance for violating children’s privacy. One user had become famous for being censored due to her camouflaged message of support for the rights of China’s Uighur minority.

Remember that the Trump administration had previously launched attacks on other Chinese companies, including ZTE Corp. and Huawei Technologies Co., while dozens more had been placed on blacklists over national security concerns.

Mayer should have seen what was coming, namely a push to either ban TikTok or force its separation from ByteDance. Yet his statement to staff, obtained by Bloomberg News, indicates he couldn’t, or wouldn’t, adapt to the change foisted upon him.

“As the political environment has sharply changed, I have done significant reflection,” the memo says. “I understand that the role that I signed up for — including running TikTok globally — will look very different as a result of the U.S. administration’s action to push for a selloff of the U.S. business.”

To be fair, the full circumstances of his resignation aren’t clear. It’s possible that Mayer was asked to leave, or that his departure was a precondition to a sale that’s due to be announced within weeks. There may be other factors that have yet to come to light, so he deserves some benefit of the doubt.

What’s not in question is the setback for TikTok and its parent, ByteDance. Mayer’s appointment brought with it the gravitas of a seasoned, experienced professional at the top of his game with more than 15 years at the world’s most-respected entertainment company. More importantly, TikTok loses a sense of Americanism that it desperately needs.

Even if the forced sale does go through — there’s a Sept. 15 deadline — TikTok will continue to face suspicion among those wary of Chinese influence, especially as the U.S. heads into a presidential election in which Beijing is a convenient scapegoat for many of the country’s troubles.

His role will temporarily be filled by General Manager Vanessa Pappas (who is of Greek-Australian heritage and a long-term U.S. resident). While a permanent CEO will also likely be a Westerner, Mayer’s short stint signals the kind of instability TikTok can ill-afford right now.