The Chinese government this week urged the U.S. not to allow Taiwanese President Tsai Ing-wen to stop over in the U.S. on her way to Belize and Paraguay this month as she has on previous trips to Latin America. It’s Beijing’s latest gambit in an ongoing campaign to wipe Taiwan off the map as an independent political entity. This campaign is forcing everyone from national governments and NGOs to airlines and clothing companies to take a stance on the contentious issue of Taiwan’s status.

Hostility between Beijing and Taipei has been growing since the 2016 election of Tsai, a nationalist who Chinese leaders suspect wants to declare formal independence. Meanwhile, Chinese President Xi Jinping’s government has been moving to assert China’s sovereignty over disputed territories elsewhere, like the Chinese-Indian border and the South China Sea as well as places with ambiguous political status, like Hong Kong.

Taiwan is probably the most important of these territories. It has been de facto independent since 1949, but China considers the island part of its territory and has long pressured other countries to see it that way as well. As China’s economic and political might has grown, it’s become harder for Taiwan to keep allies. Only 18 countries still have formal diplomatic relations with Taiwan, mostly small countries in the Pacific and Latin America, including Belize and Paraguay—the two places Tsai is visiting on her trip this month. The Dominican Republic and Burkina Faso were the most recent governments to cut ties with Taiwan in May, bowing to what the Dominican government called “socioeconomic reality.” Consequences can be serious for countries that hold out. The tiny Pacific island nation of Palau, which still has relations with Taiwan, last month asked the U.S. and Japan for economic assistance after China apparently barred tourists from traveling there, forcing one airline out of business.

It’s not just governments that are feeling the heat. Chinese pressure also led to the cancellation of the 2019 East Asian Youth Games, a multimillion-dollar sporting event that was to be held in the Taiwanese city of Taichung next year. Taiwanese LGBTQ rights activists have accused China of pressuring the organizers of next month’s Gay Games in Paris to ban the Taiwanese national flag from the competition.

Beijing set a deadline last week for 44 international airlines to drop all references to Taiwan from their websites and other materials and refer to cities like Taipei and Kaohsiung as part of China. While the consequences of ignoring the demand were never specified, all have now complied—a testament to the importance of the Chinese market. (A few have just dropped all references to countries.)

After an uproar in May, the Gap was forced to apologize for selling a T-shirt showing a map of China that did not include Taiwan, issuing a statement on microblogging site Sina Weibo affirming that it “respects the integrity of China’s sovereignty and territory.”

The White House has, rightly, denounced China’s pressure campaign against private companies as “Orwellian nonsense.” Under what’s known as the “One China” Policy, the U.S. does not formally recognize Taiwan but is nonetheless one of its most important allies and its sole foreign arms supplier. The U.S. somewhat awkwardly maintains ties to Taipei through an unofficial embassy—the American Institute of Taiwan. The U.S. opened a new $256 million office in Taipei for the AIT last month, prompting protests from the mainland.

President Trump controversially took a phone call from Tsai during the presidential transition and briefly suggested he might reverse the “One China” Policy, before quickly backing down. National security adviser John Bolton is also a longtime critic of the “One China” Policy who advocated, before joining the Trump administration, for the U.S. to play the “Taiwan card” against China, and there have been rumors that he was planning to visit the island, which would make him the highest-ranking U.S. official to do so since Washington withdrew diplomatic recognition in 1979.

While China’s request for the U.S. to shun Tsai might seem fairly petty, the long-term stakes of the Taiwan dispute couldn’t be higher. The Chinese military held a live-fire drill in the East China Sea last month to simulate combat against Taiwan. The prospect of an eventual annexation of Taiwan—or “reunification,” as Beijing puts it—is a major driver of China’s recent military buildup. It’s also one of the scariest scenarios in terms of risking military conflict between the United States and China.

For now, the best the U.S. can probably do is work to maintain the status quo—push back against pressure on American companies, maintain unofficial diplomatic relations, and allow Tsai to have her stopover—without unnecessarily escalating tensions. While frustrating and hypocritical, the ambiguity around Taiwan’s status has served the U.S. well, allowing Washington to continue de facto support for a democratic ally while continuing to do business with Beijing. But it’s not clear how much longer China will allow that ambiguity to continue.