While China's statements over House Speaker Nancy Pelosi's possible trip to Taiwan do not stray too far from what it has been saying for decades, insiders in Beijing and Washington worry that they are not empty threats.
"It's a tough call for the administration," said Michael Green of the Center for Strategic and International Studies in Washington, who helped shape Asia policy as a senior official in the George W. Bush administration.
"If they pressure Pelosi to back down, they will invite greater Chinese threats and pressure in the future and increase the odds of a crisis again down the road," he said. However, he said, "if they support her going, they risk escalating tensions in the Taiwan Strait."
"They've got to find an elegant resolution," he added.
The spiraling controversy over Pelosi's trip, which has not been confirmed by her office, has created a dilemma for both the U.S. and China amid already strained relations and growing alarm in Washington over the fate of Taiwan, a self-ruling democracy of 24 million people that Beijing claims as its territory.
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Chinese leader Xi Jinping has not ruled out the use of force to achieve "reunification." Although there are no signs of an imminent invasion, China has been ratcheting up its military activity around the island, and it claims sovereignty over the entire Taiwan Strait, which U.S. warships often transit through.
Top U.S. military officials say that in the past five years, the Chinese military has grown more aggressive not just around Taiwan, but also throughout the broader region. Beijing denies the charge, pointing instead to Washington's own more frequent military activities "on China's doorstep."
Since the news broke that Pelosi might be planning a trip to the island, Chinese officials and state media have been characteristically vehement in their opposition, repeating warnings over what they see as foreign interference in the Taiwan issue.
"Should the U.S. side insist on making the visit, China will act strongly to resolutely respond to it and take countermeasures," a Chinese Foreign Ministry spokesman said, arguing that the speaker's visit would send the wrong message to advocates of independence for the island. "We will do what we say."
Hu Xijin, the retired editor of the state-backed newspaper Global Times, went further.
"If the U.S. can't restrain her, let China restrain her & punish her," he wrote on Twitter. "[The Chinese] Air Force will surely make her visit a disgrace to herself and to the U.S."
While Washington recognizes Beijing as the official government of China, it maintains unofficial relations with Taiwan and is bound by law to provide it with defensive weapons.
Some U.S. lawmakers have been urging the White House to take a more assertive stance on Taiwan, and support for Pelosi's trip has only grown since President Joe Biden said last week that the U.S. military thought it was "not a good idea right now." In a rare display of unity, both Democrats and Republicans on Capitol Hill are urging Pelosi to go.
The controversy comes as Biden and Xi are set to hold their first phone call in four months. Topics of discussion are expected to include tensions over Taiwan, the Russian invasion of Ukraine and how to manage competition between the U.S. and China, a White House spokesman said Tuesday.
Pelosi's office has not confirmed the trip, citing security issues around any international travel by the speaker. A visit planned for April was postponed after she tested positive for the coronavirus.
Joanne Ou, a spokesperson for the Taiwan Foreign Affairs Ministry, told NBC News on Wednesday that "we have not received any definite information regarding Speaker Pelosi's visit to Taiwan." Premier Su Tseng-chang said that he appreciated Pelosi's support over the years and that foreign visitors are welcome, local media reported.
U.S. lawmakers and other current and former government officials regularly visit Taiwan, including at least two congressional delegations since April. But Pelosi, who is second in the line of succession to the presidency after Vice President Kamala Harris, would be the most senior U.S. lawmaker to visit Taiwan since Newt Gingrich went there while he was House speaker in 1997.
Pelosi is also well known in China, and she has a long history of criticizing its Communist Party government, going back to the 1989 massacre of the student-led pro-democracy protesters in and around Tiananmen Square in Beijing.
Lawmakers' visits to Taiwan are usually not announced in advance, but news of a potential Pelosi trip in August was first reported early last week by The Financial Times. Although China responded negatively, Biden's comments "raised it to a whole other level," said Julian Ku, a law professor and expert on Chinese foreign policy at Hofstra University.
"If anyone deserves the responsibility for elevating this, it's President Biden," Ku said. "Now, he may be doing so because he's getting unusually angry or unusually urgent messages from China, but we don't really know what's been said to them."
China typically expresses its displeasure with developments in Taiwan by deploying more ships in the region, sanctioning companies that sell the island weapons or sending warplanes into Taiwan's self-declared air defense identification zone, which Beijing already does regularly.
In the case of a Pelosi trip, the idea would be "avoiding direct military conflict while causing the U.S. side to feel real pain," said Ni Lexiong, a professor at Shanghai University of Political Science and Law.
"It's not clear what those actions are, and there's not much point in guessing. But there are many options," he said. "They can be political, diplomatic, economic, military; in the air, on the ground, on the water, under the water; in the South Sea of China, in the East Sea of China, in the Taiwan Strait, etc."
Zhou Bo, a senior fellow at the Center for International Security and Strategy at Tsinghua University in Beijing and a China Forum expert, said Biden should block a Pelosi trip if he believes it is in America's interest to avoid confrontation with China.
"He used to talk about the need to establish guardrails in Sino-U.S. relations," he said. "I cannot think of any guardrails more important than on avoiding miscalculations or conflict between the two countries in the Taiwan Strait."
The prospect of a Pelosi visit comes at a sensitive time, with Xi expected to seek an unprecedented third term at a party congress this year and China's People's Liberation Army celebrating the anniversary of its founding on Monday. Zhou, a former senior colonel in the People's Liberation Army, noted that the Chinese military is much stronger today than when Gingrich visited Taiwan in 1997.
"Pelosi should have known the consequences of her potential visit already," he said. "If she insists on making trouble, this will prove to be a fool's errand."
In Taiwan, where annual military drills are underway, public opinion about a Pelosi visit appeared to be mixed, with many residents saying they did not know who she was.
"I don't think she should make trouble for us locals. As soon as the firing begins, it will be us who suffer the harm, not them," said Ji Mengqian, 45, a tea shop owner in Taipei, the capital. "Look at Ukraine's situation. Nobody wants to be caught in such an endless war."
Others were more supportive.
"China has repeatedly threatened to escalate the conflict, but this will mean the U.S. has less room to retreat," said Huang Yan-cheng, 25, a student. "China's own irrational behavior will also put its neighbors on alert and on Taiwan's side."
Both Beijing and Washington now find themselves in an awkward position. If Pelosi visits Taiwan and the Chinese response is muted, that could undermine the credibility of Beijing's threats. If she appears to give in to Chinese pressure and does not go, it could be an embarrassment for the White House that would be seized on by Republicans.
"It is a bit of a staring contest," Ku said, "and both sides are going to lose a little bit."