Preventing the emergence of regional hegemons in strategic regions has been a vital American interest since the declaration of the Monroe Doctrine of 1823. Initially, the impetus for the Doctrine was keeping powerful European states out of the Western Hemisphere. As Washington grew more powerful and America’s global presence expanded, however, the formulation shifted into a broader imperative: preventing the ability of foreign nations to dominate their own hemispheres. As the twentieth century strategist Nicholas Spykman put it, “The United States is obliged to safeguard her position by making certain that no overwhelming power is allowed to build itself up” in Eurasia.[1] By 1947, American diplomats were emphasizing the need to not only prevent Soviet expansion but also to block the emergence of any single hegemon.[2]

This objective remains a vital U.S. interest today. The Trump administration said as much in the 2026 National Security Strategy when it posited that: “The United States cannot allow any nation to become so dominant that it could threaten our interests… We must prevent the global, and in some cases even regional, domination of others” (emphasis in the original).[3] That framing rests on sound logic; the United States is best defended by forward-deploying military force and cultivating alliances to maintain favorable power balances around the world, particularly in the Indo-Pacific.

As the People’s Republic of China (PRC) grows increasingly stronger and more assertive, U.S. officials will need to decide how Taiwan fits into this strategic imperative. Is Taipei’s political future inseparable from America’s longstanding effort to blunt the emergence of regional hegemons? 

Nations wage war in defense of vital interests, not secondary priorities. Relatedly, governments fight when the perceived benefit of victory outweighs the cost of war. If the U.S. could realize its strategic objectives in the Indo-Pacific without Taiwan’s de facto independence, then it would be inadvisable for Washington to defend Taipei. The opposite is also true. If Taiwan is a hinge on which America’s position in East Asia rises or falls, then the United States should be ready to fight the People’s Liberation Army (PLA), deny its objectives, and, if necessary, roll its forces back across the Taiwan Strait.

Those who argue against defending Taiwan commit two errors: understating the follow-on impacts of Beijing’s victory, and overstating America’s ability to prevent Chinese hegemony in the Indo-Pacific with the island under PRC sovereignty. The fall of Taipei would presage an economic, technological, and strategic catastrophe from which Washington would struggle to recover. It would also compromise America’s ability to constrain Beijing’s power projection capabilities and tilt the balancing/bandwagoning calculations of Indo-Pacific nations in Beijing’s favor. 

Understated Costs

The United States is overleveraged in East Asia economically, technologically, and strategically. The fall of Taiwan risks triggering crises in all three categories that Washington would struggle mightily to contain.

Economic Costs

The United States, for instance, would face a severe economic crisis if Beijing were to initiate hostilities against Taiwan. By some estimates, the projected impact on U.S. GDP would be between a 3 percent to 11 percent contraction.[4] Treasury Secretary Scott Bessent has warned industrial leaders of “an economic apocalypse” in this regard.[5] Opponents of defending Taiwan generally agree that America would suffer significantly from a blockade or invasion of the island, but some argue that the costs would be bearable. In their telling, China’s leadership would refrain from completely blocking maritime commerce in East Asia for fear of domestic economic blowback. Even if the PRC wanted to lock down the Taiwan Strait, the argument holds, alternative routes at the southern tip of the South China Sea and through the South Pacific would blunt the impact.[6]

These assumptions project American sensibilities onto China’s leadership, however. Xi Jinping has routinely prepared the Chinese people to “eat bitterness” in an effort to steel domestic resolve for dire economic scenarios.[7] More concretely, Xi has pursued a “dual circulation” policy since the COVID-19 pandemic aimed at reducing China’s economic exposure to the West and standing up vertically integrated industries at home.[8] He is, in a word, insulating the PRC to withstand economic catastrophe. But American policymakers, who are democratically accountable to voters, face fundamentally different risk calculations than do dictators. They also have fewer credible mitigating policies available in the short-term. Mirror-imaging these American realities onto China represents a fundamental analytical failure.

Moreover, America cannot assume that alternative shipping routes will conveniently appear. China could use military threats to pressure the Philippines and Indonesia to deny shipping through their archipelagos. In the South Pacific, Beijing has already invested in a robust Belt and Road Initiative (BRI) partnership with the Solomon Islands, including law enforcement and security.[9] More recently, the PLA has fired nuclear-capable ballistic missiles into the South Pacific.[10] Xi understands the strategic landscape of his own neighborhood well, and American strategists should expect him to contest any efforts to mitigate the immediate fallout over Taiwan.

Technological Costs

The United States would also face severe technological challenges. Washington cannot wish away the reality that 97 percent of high-end semiconductors are manufactured in Taiwan.[11] Opponents of defending Taiwan see a rosy future where creative export controls effectively eliminate China’s ability to benefit from the seizure of the manufacturing capabilities of the Taiwan Semiconductor Manufacturing Company (TSMC), and in which boosted domestic production of advanced chips in America makes the pain bearable.[12] Such optimism ignores China’s already proven trump card against America: export controls on refined rare earth elements. With the stroke of a pen, Xi could restrict the requisite inputs for companies to produce chips in the United States. Even if it could evade these challenges, the chip industry has yet to shift its fabrication operations away from Taiwan. If current projections hold, U.S. production may only account for 10 percent of global output in 2030—the same as it did in 2020.[13] In other words, Washington has few credible defenses if China strips Taiwan of its “silicon shield.”

Strategic Costs

Finally, American policymakers should expect a Taiwan war to quickly change the regional status quo in ways that threaten Washington’s vital interests. In the wake of deterrence failure, nations that lack the resources to develop indigenous nuclear programs will face increased pressure to bandwagon with the PRC. Those who can go nuclear, like Japan and South Korea, will be highly incentivized to do so quickly. For its part, China would face incentives to lock in additional gains before that window closes—a scenario too many analysts in Washington overlook. At a minimum, proliferation in East Asia could pressure India to boost its stockpile, which would likely trigger a similar response from Pakistan. Nonproliferation, another vital U.S. national security interest, could be imperiled in the wake of a conflict over Taiwan.

Opponents of defending Taiwan may argue that these costs, while high, are preferable to entering World War III because America can still secure its vital interests with PRC sovereignty over Taiwan. Those who make this argument, however, both misjudge America’s adversaries and misunderstand its allies. 

Misjudging Adversaries

Political debates often take the form of competing analogies. While imperfect, analogies can help make sense of the present using the lessons of the past. One historical reference that opponents of defending Taiwan have invoked is the Vietnam War. Scholars like Jennifer Kavanagh and Stephen Wertheim reference a historically unpopular war from America’s past to highlight a stark dichotomy: with Taiwan, American presidents must either enter World War III, surrender the island to Beijing, or—as they recommend—arm America’s regional allies to the teeth. As they argue, “The balance of power in Asia does not hinge on control of Taiwan.”[14]

Implicit in this belief is the assumption that China’s ambitions would be satisfied after taking Taiwan. But unifying the island with China is more likely to presage the beginning of Beijing’s geographic expansion, not its culmination. A better analogy would be that of Imperial Japan. In 1950, General Douglas MacArthur warned President Truman that empires had historically used Taiwan as

“…a springboard for military aggression directed against areas to the south. The most notable and recent example was the utilization of [Taiwan] by the Japanese in World War II. At the outbreak of the Pacific War in 1941, [Taiwan] played an important part as a staging area and supporting base for the various Japanese invasion convoys.”[15]

An even better analogy is China’s often overlooked imperial past. In 110 BC, the Han dynasty attacked Korea and established a puppet government. The Han also opened up a new front against the Xiongnu tribes to the west (in modern-day Xinjiang) and set up colonial protectorates in Central Asia. The quest for hegemony pervaded successive dynasties. The Sui invaded Korea four times. The Tang solidified Chinese colonies in Xinjiang, expanded its presence to the border of the Persian Empire, and attacked Tibet. The Yuan, a Mongol dynasty, invaded Japan twice, southern Vietnam, and Burma, and made Thailand a vassal state. The Ming punished numerous rulers of island kingdoms in the South China Sea and Bay of Bengal who bucked the tribute system. The Qing, a Manchu dynasty, committed genocide in Central Asia and formally annexed Xinjiang. According to the Chinese Academy of Military Sciences, the in-house think tank of the PLA, from 1100 BC to AD 1912, China waged 3,790 wars. On average, dynastic China never knew a year without war.[16]

This history lives on in Xi Jinping’s mind. Recall Xi’s ominous comment to President Trump in 2017 that Korea “actually used to be a part of China,”[17] and Beijing’s penchant for advancing its claim to Japan’s Ryukyu’s archipelago.[18] Despite the Chinese Communist Party’s efforts to whitewash its territorial ambitions for American and European audiences, its flagship Belt and Road Initiative (BRI) project is the clearest evidence that Beijing still harbors imperial designs.[19]

By ignoring these risks, opponents of defending Taiwan commit the same mistake Secretary of State Dean Acheson made during his infamous 1950 remarks at the National Press Club, the same year as MacArthur’s Taiwan memorandum. Historians remember Acheson’s speech for his notable exclusion of South Korea and Taiwan in his definition of America’s defensive perimeter in Asia. Largely forgotten is his misguided assessment of China. Acheson proposed a simple rule to guide U.S. policy in Asia: “anyone who violates the integrity of China is the enemy of China and is acting contrary to our own interest.”[20]

To be sure, the Secretary saw evidence that Moscow was making this mistake at the time. In his telling, the Soviet Union’s designs on Manchuria, Inner Mongolia, and Xinjiang would put Moscow and Beijing at loggerheads, and America should reap the benefits. Acheson’s observations were misguided because he confused realpolitik with first principles.[21] The first rule of American grand strategy is the protection of vital interests, not deference to the interests of others. America’s chief objective in Asia has always been to prevent the emergence of a regional hegemon there.

Misunderstanding Allies

Some who advise against supporting Taiwan in the event of war respond that America’s vital interests are not at stake with Taiwan, even if the costs of losing it to the PRC are high.[22] Central to their argument is the belief that U.S. allies have the capacity to balance against China with sufficient American support and robust defense investments. Geography complicates these assumptions, however. Consider this analysis of Japan’s security environment from Gabriel Collins, Andrew Erickson, and Matt Pottinger:

“Japan’s defensive concept relies on its ability to hold at-risk PRC naval vessels and warplanes that venture near, through, and beyond what is informally known as the First Island Chain. For Japan’s defensive posture to work, the full island chain, which includes the Japanese and Philippine archipelagos as well as Taiwan at the center, must remain in the hands of friendly powers.”[23]

Beijing is aware of the acute vulnerability Tokyo would suffer if Taiwan were to fall. Indeed, PLA military textbooks openly discuss this scenario:

“As soon as Taiwan is reunified with mainland China, Japan’s maritime lines of communication will fall completely within the striking ranges of China’s fighters and bombers… Our analysis shows that, by using blockades… Japan’s economic activity and war-making potential will be basically destroyed… Blockades can cause sea shipments to decrease and can even create a famine within the Japanese islands.”[24]

By ignoring these realities, analysts today repeat yet another mistake of Acheson and his contemporaries: failing to recognize that geography imposes constraints upon allies and shapes their security situation, even if those conditions themselves are not tied directly to America’s vital interests.[25] It was not without reason that Japanese Prime Minister Sanae Takaichi warned in November 2025 that a war over Taiwan would be “a survival-threatening situation” for Tokyo.[26]

The Irony of Retrenchment

Opponents of defending Taiwan include experts who advocate for shifting America’s strategic focus away from priority theaters in Europe and the Middle East toward the Indo-Pacific. Colloquially, proponents of these views are often called “prioritizers” or “retrenchers.” Both names reflect the belief that America’s commitments exceed its resources, and that policymakers should concentrate scarce capabilities in the theater where the nation’s most vital interests lie.

Washington had a similar debate 75 years ago, largely forgotten today. We are rehashing an old conversation that unfolded contemporaneously with the Korean War. Because too many in Washington are unfamiliar with this history, policymakers are expending unnecessary energy on re-learning the lessons of prior generations. Bringing this history back into Taiwan debates today is desperately needed.

When Acheson proposed non-aggression against China as the lodestar of America’s Asia policy in 1950, many in the U.S. national security community agreed. In 1949, the Joint Chiefs of Staff argued that Taiwan was “strategically important” to the United States, but that military force to defend the island was inadvisable “so long as the present disparity between our military strength and our global obligations exist.”[27] According to the Joint Chiefs, two factors contributed to this disparity: budgetary limitations, and the prioritization of the European theater. They noted, however, that “future circumstances” could change their assessment. 

Within a year, those circumstances had arrived in the form of the Korean War. By 1952, the Joint Chiefs termed the denial of Taiwan to Communism of “vital importance to the long-term United States position in the Far East.”[28] The following year, a top-secret National Security Council document recommended “taking all necessary measures to prevent hostile forces from gaining control” of Taiwan, “even at grave risk of general war.”[29]

Seventy-five years ago, the conventional wisdom in Washington was that Europe, not the Indo-Pacific, was America’s priority theater. It took the Korean War to alter that perception. 

Today, the retrenchers have learned half of this lesson: they correctly identify the Indo-Pacific as the region most vital for U.S. interests. Unlike post-World War II leaders, however, many of them remain unwilling to fight for America’s interests there. 

America’s abiding interests in Taiwan remain unchanged, however. The island is the same “unsinkable aircraft carrier” it was in 1950.[30] Japan cannot defend itself without Taiwan ruled by a friendly government. And because Japan is central to America’s presence in the first island chain, Taiwan’s future is inseparable from Washington’s interests there.

Retrenchers are right that the costs of war are high. They are wrong that cheaper options exist to prevent China from achieving regional hegemony. For better or worse, securing America’s vital interests runs straight through an island nearly 8,000 miles away, roughly the size of Maryland, with a population comparable to that of Florida—and which sits about a hundred miles off China’s coast.