The US's One-China Policy Explained

PHOTO: Donald Trump speaks during his meeting with President Barack Obama in the Oval Office of the White House in Washington, Nov. 10, 2016. Xi Jinping looks on before a meeting at the Great Halll of the People, Dec. 2, 2016, in Beijing, China. PlayAP Photo/Getty Images
WATCH One-China Policy: The Basics

President-elect Donald Trump's unprecedented phone call with the leader of Taiwan on Friday, followed by his anti-China tweets on Sunday, signal strongly that upon taking office next month he could seek to deviate from America's long-standing one-China policy.

Trump's phone call with Taiwanese President Tsai Ing-wen on Friday (which he says was initiated by Taiwan) prompted headlines across the U.S. that Trump had broken with decades-old policy and even forced the White House to respond and affirm its commitment to current policy.

Secretary of State John Kerry said over the weekend that it "would be helpful" if the president-elect's transition team consulted with the State Department before speaking with foreign leaders.

So what is the U.S. position on China and Taiwan, and why is it so delicate?

One-China, Briefly

Since the signing of the Taiwan Relations Act in 1979, it has been the policy of the United States to recognize Taiwan as part of China.

"The United States does not support Taiwan independence," reads a State Department fact sheet updated just this September. But, it continues, "maintaining strong, unofficial relations with Taiwan is a major U.S. goal, in line with the U.S. desire to further peace and stability in Asia."

Taiwan is the United States' ninth-largest trading partner, and according to State Department figures, Taiwan employed more than 12,000 workers in the United States and paid them nearly $1 billion. The one-China policy amounts to a delicate balance between respecting China's claim to the territory and maintaining close ties to Taiwan.

Missiles Pointed

The U.S. commitment to Taiwan permits the sale of defensive weapons, and last year the U.S. sold Taipei $1.83 billion worth, most of which it uses to defend the island from a potential provocations from Beijing.

That last package, the first of its kind in four years, consisted of two Oliver Hazard Perry class Navy frigates, Javelin anti-tank missiles, amphibious assault vehicles, anti-aircraft missiles, anti-ship systems and other equipment.

Since 1979, the U.S. has made $12 billion in weapons sales to Taiwan, and Beijing voices its opposition every time.

A State Department official told ABC News today that the U.S is constantly reviewing Taiwan's defensive needs and requests and will continue to do so. "We do not consult Beijing about our military cooperation with or arms sales to Taiwan," this official said.

Despite the weapons sales and the importance of good relations emphasized by both sides, Taiwan is not a treaty ally with the United States, and the U.S. has no obligation to defend it if it is attacked.

Trump's Approach

ABC News learned today that Trump's congratulatory call from Tsai was expected and likely arranged by people in his transition team. So while it was a surprise to China and many in the U.S. government, Trump's advisers are claiming it was calculated.

Trump took a firm stance on confronting a rising China during his campaign, repeatedly accusing China of manipulating its currency and once saying, "We already have a trade war [with China]," suggesting he doesn't fear an escalation.

He also floated the idea of imposing major tariffs on Chinese products. "We have the power over China, economic power, and people don't understand it," he said in April.

He opposes the Trans-Pacific Partnership, which effectively leaves the future trade relationship with China undecided.

China's Response

The Chinese government has yet to issue a public rebuke of the phone call, but a Foreign Ministry spokesman told reporters today that Beijing has been in contact with Trump's team since the call and suggested that it made its concerns known directly.

However, the Foreign Ministry does not wield the same power as the party leadership, and a more meaningful reaction would come from that office or from the Chinese military.

Those bodies might not offer a response until Trump is in office and dictating policy.

China's state-owned English newspaper, The China Daily, published an editorial on Saturday that read, "For Trump, it exposed nothing but his and his transition team’s inexperience in dealing with foreign affairs."