Why Taiwan and the South China Sea Are Flashpoints for the US and the World

The strategic importance of Taiwan and the South China Sea has come under renewed scrutiny after a US senator stumbled in a debate over whether Washington has a national security interest in the region. Senator Darline Graham, who is seeking a full term in South Carolina, drew criticism for saying national security was "not my thing." Her late brother, Lindsey Graham, had been a vocal figure in foreign policy, including trips to Taiwan.

Taiwan and the South China Sea have long been pillars of US foreign policy in the Asia-Pacific. Beijing claims Taiwan as its own territory and asserts sovereignty over nearly all of the South China Sea, putting it at odds with US allies and partners. The stakes are global: Taiwan produces most of the world's advanced semiconductors, while the South China Sea is one of the busiest maritime trade corridors, linking the Pacific and Indian Oceans through chokepoints like the Malacca Strait.

Experts note the two are strategically connected. Hunter S. Marston, director of the Southeast Asia Program at the Lowy Institute, said that if China were to blockade or forcibly take Taiwan, the South China Sea could see immediate spillover effects. A conflict could also require the evacuation of nearly one million citizens from ASEAN countries and force regional governments to navigate between Washington and Beijing.

China has not renounced the use of force to bring Taiwan under its control, and it regularly sends military aircraft and ships near the island. The US has no formal diplomatic ties with Taiwan but is legally bound to provide it with the means to defend itself. That arrangement has long been a source of friction with Beijing. During President Donald Trump's May visit to Beijing, Chinese President Xi Jinping called Taiwan the most important issue in bilateral ties, warning that mishandling it could lead to confrontation. Trump did not address Taiwan publicly but later called arms sales to the island a "very good negotiating chip."

In the South China Sea, China's expansive claims were invalidated by a 2016 international arbitration ruling, which Beijing rejects. On the ruling's 10th anniversary in July, the US, UK, and 12 other countries reiterated that the claims have no legal basis. Confrontations have escalated, with Chinese vessels using water cannons and lasers against Philippine and Vietnamese forces. China also held military drills near Scarborough Shoal this month, while the US and Philippines conducted their annual Balikatan exercises in April.

For the US, the primary interest is preventing China from dominating the Pacific, according to Marston. The security of Taiwan and allies like the Philippines, along with the defense of the first island chain, are central to that goal. But the US military's ability to maintain a presence in the western Pacific is being tested. The USS George Washington is leaving for the Middle East to replace the USS Abraham Lincoln, temporarily leaving the region without a US aircraft carrier at a time of heightened tensions.