The importance of defending Taiwan from Chinese aggression

 Time:

...

Physically, Taiwan sits astride some of the world’s busiest shipping lanes and prevents China from projecting power far beyond its shores. If China were to annex Taiwan and station its military on the island, it would be able to limit U.S. military operations in the region and hamper our ability to defend our allies.

Geopolitically, should we fail to counter Chinese aggression against Taiwan, our allies would have doubts about whether they could rely on us. China’s military, if occupying Taiwan, would be only seventy miles from Japanese territory and 120 miles from the Philippines. Our allies, questioning whether we would or even could come to their defense, would be faced with a difficult choice: drawing closer to China or taking their security into their own hands, potentially to include developing nuclear weapons. Either outcome would result in diminished U.S. influence and increased regional and global instability.

Economically, given Taiwan’s dominance of semiconductor manufacturing, Chinese aggression would also trigger a global economic depression and shave trillions of dollars off economic output. During a Chinese blockade or attack, Taiwan’s production and shipment of semiconductors would come to a halt, leading to a shortage of nearly every product that contains technology, from smartphones to computers and cars.

Ideationally, Taiwan’s fate also has implications for international order, which have been magnified by Russia’s invasion of Ukraine. If China were to successfully absorb Taiwan, it would establish a pattern of authoritarian countries using force to attack democratic neighbors and change borders. The most basic pillar of international relations—that countries cannot use force to alter borders—would be severely undermined.

Taiwan is one of Asia’s few democratic success stories, but if China were to take the island by force its democracy would be extinguished, and its twenty-three million people would see their rights severely curtailed. As this would come in the wake of China’s crackdown on democracy in Hong Kong, the ramifications would be even greater.

Read More: Why Protecting Taiwan Really Matters to the U.S.

The stakes are clear, but our Task Force assesses that deterrence is eroding and is in danger of failing. While a military confrontation in the Taiwan Strait is neither imminent nor inevitable, the U.S. and China are drifting toward a war over Taiwan. U.S. policy will need to evolve to contend with a more capable, assertive, and risk-acceptant China that is increasingly dissatisfied with the status quo.
...

A significant portion of the population of Taiwan is made up of Chinese from the mainland who left China when the communists took over.  They have made Taiwan a prosperous country.  The Chinese military has not demonstrated a capacity for operations like those that would be required for taking Taiwan, but they could develop it by copying US amphibious operations. 

See, also:

3 major companies trying to move supply chains out of China, and how they're faring in their attempts to move away from the factory of the world