China on Monday hit out at 'unruly' comments from U.S. president-elect Donald Trump, who suggested Washington could use the status of Taiwan as a bargaining chip in bilateral trade negotiations with Beijing.
Trump questioned the One China policy on Sunday during an interview with Fox News to discuss his phone call from Taiwan president Tsai Ing-wen.
"I don't know why we have to be bound by the One China policy unless we make a deal with China having to do with other things, including trade," he said.
His comments come after four decades of consensus between Beijing and Washington that Taiwan, which has never been ruled by the Chinese Communist Party, is part of a single, Chinese territory, but currently under a different government.
"His unruly words and deeds are regarded by many observers, even in the U.S., as transactional and having broken decades of U.S. diplomatic principles and traditions," the Global Times newspaper quoted an expert at a ruling Chinese Communist Party-backed think-tank as saying.
"His remarks have not only jeopardized world peace, but also upset the Beijing-Washington relationship," it quoted Niu Xinchun, top U.S. analyst at the China Institutes of Contemporary International Relations, as saying.
Niu, whose view represents the political orthodoxy in Beijing without carrying formal diplomatic weight, warned that "subversion" of the current relationship would have serious consequences.
While the foreign ministry's response was more measured, it too spoke of "serious concern," and warned that any bilateral cooperation would be "out of the question" if the U.S. abandoned the One China policy.
"China has noted the report and expresses serious concern about it," foreign affairs spokesman Geng Shuang told a regular news briefing in Beijing.
"I want to stress that the Taiwan issue concerns China's sovereignty and territorial integrity, and involves China's core interests," he said.
China's red line
He said questioning the One China policy would damage bilateral relations. "Bilateral cooperation in important areas [would be] out of the question," Geng said.
Top Chinese diplomat Yang Jiechi has already met with Trump's advisers, and exchanged views on "important issues," Geng said, but gave no further details.
Gao Xin, a U.S.-based democracy activist turned political commentator, said a Chinese invasion is a distinct possibility, should either Trump or Taiwan continue to cross Beijing on this issue.
"It won't matter who crosses the red line; the consequences will be very serious," Gao wrote in a recent commentary for RFA's Mandarin Service.
"If there is a breakdown on the general principal that the U.S. has no official ties with Taiwan, then that will be a deal-breaker for Beijing," he said.
"If that happens, then mainland Chinese will proceed to ignore all the other 'red lines'," Gao wrote.
He cited Beijing's Anti-Secession Law passed March 14, 2005, providing for "non-peaceful means and other necessary measures," should Taiwan seek to "separate" from China.
"The law is rigid, the army is determined, and there is more than one way of settling the Taiwan issue," he said.
Repeated polls have shown that many of Taiwan's 23 million residents identify as Taiwanese rather than Chinese, and that there is broad political support for de facto self-rule, if not formal independence.
President Tsai's Democratic Progressive Party (DPP), which swept to power earlier this year amid fears of growing Chinese influence over Taiwan under her predecessor Ma Ying-jeou, still has a staunchly pro-independence wing, in spite of repeated warnings of military intervention from Beijing.
While Tsai has pledged to maintain peaceful ties with Beijing, she has stopped short of endorsing Beijing's insistence that the island she governs is an inalienable part of a divided China.
The Kuomintang (KMT) nationalist party, which represented the island at the 1992 talks, had regarded itself as the legitimate rulers of a post-1911 Republic of China that was "temporarily" relocated to Taiwan after losing a civil war to Mao Zedong's communists in 1949.
But Taiwan was governed separately from mainland China throughout the Japanese occupation (1895-1945) and since 1949, and has never been part of communist China.
Macau-based Chinese military analyst Wong Dong said both sides are posturing, and testing the waters before Trump takes office, however.
"Trump can say a lot of things before he actually takes office, so as to sound out China's bottom line," Wong said. "Both sides are still in a bargaining phase, and for the moment, it's still a war of words."
"As for whether they will attack Taiwan, they're not ready to do that yet, and even if the U.S. was going to strike such a [diplomatic] blow to China, China wouldn't need to attack quite so fast," he said.
"The Taiwan issue is being used as an excuse for a game of political chicken, to try to make the other side back down."
Hui Ching, research director at the Hong Kong Zhiming Institute, said Beijing can't back down, however.
"This issue is the guiding principle in all their diplomatic relations, and China now packs 100 times the punch it used to," Hui said.
"There is no room for compromise whatsoever, and if they battle it out, it will result in a lose-lose situation for both sides," he said.
Reported by Wong Lok-to for RFA's Cantonese Service, and by the Mandarin Service. Translated and written in English by Luisetta Mudie.