(NewsNation) — As President Joe Biden returns to the U.S., tensions remain in Asia.

Separated from mainland China by the Taiwan Strait, Taiwan sits roughly 100 miles to the southeast. Although war is not imminent, Taiwan is preparing a resistance in the event China carries out an invasion.

Russia’s invasion of Ukraine has escalated tensions in Taiwan. On Monday, Biden announced that the U.S. would intervene militarily if China were to invade.

The 1979 Taiwan Relations Act, which has governed U.S. relations with the island, does not require the U.S. to step in militarily to defend Taiwan if China invades, but makes it an American policy to ensure Taiwan has the resources to defend itself and to prevent any unilateral change of status in Taiwan by Beijing.

At the end of World War II, Japan surrendered the island to the Republic of China. In the past 30 years, Taiwan has seen a massive identity shift.

In the early 1990s, less than 20% of people on the island identified as exclusively Taiwanese. Most civilians saw themselves as at least partly Chinese.

By 2021, less than a third of people identified themselves as both Chinese and Taiwanese. The other two-thirds of Taiwan’s population describes themselves as exclusively Taiwanese.