US House Speaker Nancy Pelosi visits Taiwan

During the Chinese civil war, the United States backed the ruling Nationalist government, led by the Kuomintang. The Soviet Union supported the Chinese Communist Party, which eventually took power and established the People’s Republic of China.

The US continued to support the Kuomintang, or KMT, government after it retreated to Taiwan following its defeat. The US provided the KMT with development assistance to build its economy and initially shunned the People’s Republic as an ideological and military adversary.

But following a diplomatic conflict between Beijing and Moscow in the 1960s — known as the Sino-Soviet split — relations between the US and the People’s Republic began to thaw.

By 1979, the US had joined a growing list of nations to formally switch diplomatic recognition from Taipei to Beijing.

The One China policy: In what is known as the “One China” policy, Washington recognizes the People’s Republic of China as the sole legitimate government of China. It also acknowledges Beijing’s position that Taiwan is part of China. However, the US has never accepted the Communist Party’s claim of sovereignty over the island.

Meanwhile, the US continues to retain close unofficial ties with Taiwan under the terms of the decades-old Taiwan Relations Act, facilitating commercial, cultural and other exchanges through the American Institute in Taiwan — the de facto US Embassy in Taipei.

Strategic ambiguity: The US maintains close unofficial ties with Taiwan, and is bound by law to provide Taiwan with defensive arms. But it remains deliberately vague on whether it would defend Taiwan in the event of a Chinese invasion, a policy known as “strategic ambiguity.”

This is meant to dissuade any such invasion by keeping open the possibility of a US military response. At the same time, it’s meant to avoid giving Taiwan the sort of assurance that could prompt it to declare official independence. The goal is to preserve the status quo and to avoid a war in Asia — and so far it appears to have worked, allowing Washington to walk the tightrope of relations with both sides.

Biden’s remarks: But under Biden, some observers say that “strategic ambiguity” has become somewhat less ambiguous. Since taking office, Biden has said on three occasions the US would be willing to intervene militarily should the Chinese attack Taiwan — though the White House has rushed to walk back his remarks each time.

Read more about China-Taiwan tensions here.