Donald Trump is talking about Taiwan again - and so is China, in angry and mocking comments Monday that questioned whether the president-elect grasps a core element of relations between the world's top economic powers.
In an interview broadcast Sunday, Trump said the United States would not necessarily be bound by the one-China policy - the diplomatic understanding that underpins ties between Washington and Beijing and that leaves China's rival Taiwan on the diplomatic sidelines with the United States.
Trump suggested the policy could be revisited unless America could "make a deal," potentially on trade between the two countries.
The remark elicited a sharp response from Beijing, with the Foreign Ministry expressing "serious concern" and a party-controlled newspaper calling the president-elect "as ignorant as a child."
By appearing to treat Taiwan as just a bargaining chip for trade deals, he may also have irked Taipei, experts said.
The comment came less than two weeks after the president-elect made headlines by taking a phone call from Taiwan's leader, Tsai Ing-wen, a surprise move that was interpreted by some as a high-stakes slip-up and by others as an overdue show of support for a democratic friend.
Trump's latest foray into East Asian affairs came when he was asked by "Fox News Sunday" about the planning for the Dec. 2 call. He said that he learned about the call "an hour or two" before it took place but that he understood the stakes.
"I fully understand the one- China policy, but I don't know why we have to be bound by a one-China policy unless we make a deal with China having to do with other things, including trade," he said.
"I mean, look," he continued, "we're being hurt very badly by China with devaluation; with taxing us heavy at the borders when we don't tax them; with building a massive fortress in the middle of the South China Sea, which they shouldn't be doing; and, frankly, with not helping us at all with North Korea."
"I don't want China dictating to me," he said.
Since winning the U.S. presidential election, Trump's public comments and tweets on East Asian politics have put the region on edge and thrown the future of U.S.-China and U.S.-Taiwan relations into question.
When Trump took a call from Tsai, he broke with decades of diplomatic practice - indeed, it was the first such call since President Jimmy Carter switched diplomatic recognition from Taiwan to China in 1979. The call was condemned by China, which lodged an official complaint in Washington.
State Department spokesman John Kirby said the Obama administration remains "firmly committed" to the one-China policy, even as he acknowledged that the U.S. stance may change in less than six weeks if the new administration pursues an entirely different policy.
"We have continued what has been a bipartisan approach for the past 40 years with respect to a one-China policy, and this administration continues to believe that serves our national security interests in the best possible way," he said. "The next administration, the president-elect, will have to make these decisions for himself and for themselves."
A Monday editorial in the Global Times, a state-controlled newspaper known for its strident nationalism, suggested that Trump ought to read some books on U.S.-China ties. It also warned that if the United States abandoned the one-China policy, Beijing would have no reason to "put peace above using force to take back Taiwan."
"China needs to launch a resolute struggle with him," the editorial said. "Only after he's hit some obstacles and truly understands that China and the rest of the world are not to be bullied will he gain some perception.
"Many people might be surprised at how the new U.S. leader is truly a 'businessman' through and through," the paper said. "But in the field of diplomacy, he is as ignorant as a child."
Su Hao, director of the Center for Asia-Pacific Studies at China Foreign Affairs University in Beijing, said Trump's comment was a "careless and irresponsible" act that could "shake the foundation of the bilateral relationship."
The stance on Taiwan, he said, is not open for negotiation. "International politics is not business. Not everything is on the table for trade."
Taiwan might actually agree - but for different reasons.
Many in Taipei hailed the call between Trump and Tsai as a breakthrough - a sign that the thriving democracy might finally get the U.S. backing it says it deserves. They did not see the call as a slip-up or a diplomatic gaffe but rather as the product of a Republican-led recalibration of U.S. foreign policy that has been years in the making.
William Stanton, a career diplomat who served as de facto U.S. ambassador to Taiwan from 2009 to 2012 and now heads the Center for Asia Policy at Taiwan's National Tsing Hua University, said Trump's comment Sunday seemed to throw that idea into question by treating Taiwan's status as just an element of trade negotiations.
"Either he doesn't know what he is talking about, or he is endangering the status that Taiwan has always had in U.S. policy," he said. "Having done a good thing, from my point of view, Trump has undone it."
Wu Jieh-min, an associate research fellow at Taipei's Academia Sinica, said the United States should not use Taiwan as a means to an end.
"Trump's call with President Tsai may signal a possible readjustment of the U.S. policy toward Taiwan and China respectively," he said.
"But from the perspective of the Taiwanese people," he said, "the legitimate principle should be that Taiwan should not be used as something for trade between the great powers."
The Washington Post's Luna Lin contributed from Beijing.