US-China tensions: Why is Taiwan a flashpoint?

Watch: Pelosi says China cannot stop US officials from visiting Taiwan

Tensions between the US and China have soared after Beijing launched its biggest-ever military drills around Taiwan.

Beijing began three days of missile tests near the self-governing island on Thursday, prompting fears of a military crisis in the region.

It came after US House Speaker Nancy Pelosi visited Taiwan to pledge "ironclad" support for its democratically elected government.

The Chinese regime reacted with fury, calling her visit "manic" and "irrational".

Here is everything you need to know about the tensions.

Why is Taiwan a flashpoint in US-China relations?

Taiwan has long been a flashpoint in relations between the US and China.

The island has been self-governing since nationalist forces fled there in 1949 after the communists took control of China.

TAIPEI, TAIWAN - AUGUST 03: Speaker of the U.S. House Of Representatives Nancy Pelosi (D-CA), left, poses for photographs with Taiwan's President Tsai Ing-wen, right, at the president's office on August 03, 2022 in Taipei, Taiwan. Pelosi arrived in Taiwan on Tuesday as part of a tour of Asia aimed at reassuring allies in the region, as China made it clear that her visit to Taiwan would be seen in a negative light. (Photo by Handout/Getty Images)
Nancy Pelosi's meeting with Taiwan president Tsai Ing-wen has angered China. (Photo by Handout/Getty Images)

Beijing considers it a "rebel province" which will eventually be "reunified" with mainland China.

It opposes any engagement by Taiwanese officials with foreign governments, which is why Pelosi's visit was so controversial.

Read more: China scolds G7 foreign ministers over Taiwan statement

The House Speaker is the most high-profile US politician to have visited Taiwan in 25 years.

She told Taiwanese president Tsai Ing-wen: "Today the world faces a choice between democracy and autocracy.

"America's determination to preserve democracy, here in Taiwan and around the world, remains ironclad."

Video screenshot shows a missile launched by the rocket force of the Eastern Theater Command of the Chinese People's Liberation Army PLA, targeting designated maritime areas to the east of the Taiwan Island, Aug. 4, 2022. The Eastern Theater Command on Thursday conducted joint combat exercises and training around the Taiwan Island on an unprecedented scale. (Photo by Xinhua via Getty Images)
China launched a wave of missile tests after Pelosi's short trip to the island. (Photo by Xinhua via Getty Images)

China repeatedly warned Pelosi to call off her trip – which was part of a wider tour of Asia – and launched missile drills once she left.

In addition, President Joe Biden publicly raised concerns over the visit, saying the US military felt it was "not a good idea right now".

His administration does not support independent for Taiwan, which is recognised by just 13 countries.

PA Graphics
China considers Taiwan to be a "rebel province". (Graphic by PA Graphics)

What is the 'One China' policy?

In 1979, the US closed its embassy in Taipei in order to recognise Beijing as China's only government.

This established Washington's 'One China' policy, which remains an important part of US diplomacy in the region.

Under this principle, Washington acknowledges – but does not endorse – Beijing's claim that Taiwan is part of China.

This policy of "strategic ambiguity" allows the US to have informal diplomatic ties with Taiwan, including the sale of arms to the island.

However, Washington does not say whether it would directly intervene if China was to attack or invade the island.

WASHINGTON, DC - AUGUST 01: U.S. President Joe Biden speaks from the Blue Room balcony of the White House on August 1, 2022 in Washington, DC. Biden announced that over the weekend, U.S. forces launched an airstrike in Afghanistan that killed al-Qaeda leader Ayman Al-Zawahiri. Zawahiri, 71, took over leadership of al-Qaeda in 2011, shortly after American forces killed Osama bin Laden. The president said there were no civilian casualties.  (Photo by Jim Watson-Pool/Getty Images)
Joe Biden raised concerns over Pelosi's visit to Taiwan. (Photo by Jim Watson-Pool/Getty Images)

How has the world responded?

China's foreign minister Wang Yi described Pelosi's visit as "manic, irresponsible and extremely irrational".

Meanwhile, Taipei's military says it was "preparing for war without seeking war".

Foreign ministers from the G7 nations, which include the UK, US and France, said China's actions "risk unnecessary escalation".

Chinese military helicopters fly past Pingtan island, one of mainland China's closest point from Taiwan, in Fujian province on August 4, 2022, ahead of massive military drills off Taiwan following US House Speaker Nancy Pelosi's visit to the self-ruled island. - China's largest-ever military exercises encircling Taiwan kicked off on August 4, in a show of force straddling vital international shipping lanes after a visit to the island by US House Speaker Nancy Pelosi. (Photo by Hector RETAMAL / AFP) (Photo by HECTOR RETAMAL/AFP via Getty Images)
Chinese military helicopters fly past Pingtan island, one of mainland China's closest point from Taiwan. (Photo by Hector Retamal / AFP)

They also urged Beijing against seeking to "unilaterally change the status quo by force" in the region.

In separate comments, the UK's foreign secretary Liz Truss criticised China's "inflammatory" response to Pelosi's trip.

Russia, a close ally of China, called the visit a "clear provocation" and said Beijing "has the right to take measures to defend its sovereignty".

North Korea used Pelosi's trip to accuse the US of being "the root cause of harassed peace and security in the region".