President Joe Biden’s recent pledge to defend Taiwan has ignited renewed controversy. When asked if he “was willing to get involved militarily to defend Taiwan” during his visit to Asia on May 23, he answered yes, adding: “That’s the commitment we made.” His remarks are apparently in contradiction with “strategic ambiguity,” the decades-long U.S. policy toward Taiwan that is deliberately ambivalent about the extent of the United States’ commitment to come to the aid of Taiwan. Although the White House, Secretary of Defense Lloyd Austin, and later Biden himself denied that the statement reflects a change in U.S. policy, it is unclear whether this was another gaffe by the president or a deliberate statement aimed at enhancing deterrence against China (adding ambiguity to strategic ambiguity), particularly given that this was not the first time Biden expressed his commitment.

The ambiguity of America’s policy over Taiwan is aimed at maintaining the status quo—both by reining in enthusiasm for Taiwanese independence and deterring China’s invasion of Taiwan. When the United States normalized diplomatic relations with China in 1979, it adopted the One China policy, which recognizes the People’s Republic of China as the “sole legal government of China,” and acknowledges China’s position that Taiwan is part of China, but stops short of recognizing China’s sovereignty over Taiwan. The United States severed diplomatic relations with Taiwan, but the two countries have maintained a tight, albeit unofficial, relationship. The United States has refrained from offering Taiwan an explicit security guarantee, but has provided Taiwan with arms to help it defend itself pursuant to the 1979 Taiwan Relations Act.

Strategic ambiguity may not remain as a viable policy for too long in light of the increasing assertiveness of Beijing’s claims to Taiwan. Taking back Taiwan has always been Beijing’s goal, but Beijing has stepped up its pressure on Taiwan since Tsai Ing-wen, a pro-independence leader from the Democratic Progressive Party, was elected in 2016, for example by increasing the frequency of military exercises in the vicinity of Taiwan. Although Beijing prefers a peaceful reunification, it has never renounced the use of force. As a chilling reminder, Xi Jinping said that China reserves “the option of taking all necessary means” to reunify with Taiwan. Many believe that China will likely seek to reunify with Taiwan by 2049, the centennial anniversary of the establishment of the People’s Republic of China, at the latest. Some warn that this could happen as early as 2027, based on the target date by which Beijing hopes to achieve the ability to counter U.S. intervention in the Western Pacific.

What this means for U.S. policy is that the time may eventually come for the United States to decide: should the United States defend Taiwan if China invades? Experts differ on whether the United States should defend Taiwan. The American public is divided on this issue, as well. According to a survey conducted by the Chicago Council in 2021, 52 percent of the respondents supported using U.S. troops to defend Taiwan, though this marked a significant increase from 2020 when only 40 percent supported such a proposal.

In order to decide whether defending Taiwan is sound U.S. policy, we should first articulate what is really at stake. Smart foreign policy is based on a clear understanding of national interest. Is Taiwan a matter of vital, or only peripheral interest? Does Taiwan matter to the United States, and if so, why?

There is no consensus on this issue. Some argue that Taiwan per se is not a vital interest for the United States, but China’s invasion of Taiwan would be “such a significant breach of international norms as to become a vital American interest.” Others view that defending Taiwan is of economic importance given its importance in global supply chains, especially in the semiconductor industry—Taiwan accounts for 92 percent of global production of microchips below 10 nanometers. Still others view no strategic value in Taiwan.

The fact of the matter is that the U.S. stake in Taiwan is far higher than many believe: U.S. primacy in the Western Pacific. If Taiwan falls, so does the United States’ primacy in the Western Pacific, which in turn would diminish the United States’ position globally.

Occupying Taiwan would significantly increase China’s power projection capability in the Western Pacific. It would allow China to break through the so-called “first island chain,” running through the Kuril Islands, Japan, Okinawa, Taiwan, and the Philippines. Originally envisioned by American strategists to surround the Soviet Union and China during the Korean War, the first-island chain has received renewed attention with the rise of China. In the struggle between China seeking to push the United States out of the Asia-Pacific and secure its “rightful place” in the vast Pacific Ocean, and the United Stations seeking to contain China’s expansion, the first-island chain is the first line of defense/offense depending on which side you sit. Beijing seeks to deny America access to the island chain through its anti-access/area denial (A2/AD) strategy. The United States, for its part, seeks to fortify the island chain. At the center of the first island chain is Taiwan. Two channels near Taiwan, the Bashi Channel to the south of the island, and the Miyako to the north, now constitute choke points for China. With Taiwan under Beijing’s control, these channels could serve as entryways to the Pacific. This is why Taiwan would likely be a flashpoint if a conflict breaks out between the United States and China.

In addition, reunification with Taiwan would help China carve out a sphere of influence in Asia. If Washington failed to defend Taiwan, the United States’ credibility as a reliable ally would evaporate, leaving countries in the region no option but to bandwagon to the side of China. Already today, countries in the region, including the United States’ allies and partners, are wary of siding too closely with the United States’ efforts to contain China in order not to irk their most important economic partner. For example, South Korea pledged not to expand American missile defense systems, the 2017 deployment of which prompted severe economic sanctions by China. Even Japan, the United States’ most reliable ally in the region, has avoided hosting the U.S. intermediate-range missiles aimed at countering China’s A2/AD strategy. Failing to defend Taiwan from Chinese aggression would cause the United States’ Indo-Pacific allies to lose faith in the U.S. will and/or capability to follow through on its security guarantees. Lacking U.S. support, allies would decide their efforts to balance against China are futile, and become more willing to acquiesce to Chinese demands, for example expelling U.S. troops out of their countries. These reverberations would mark the change of command of the Western Pacific from the United States to China.

Once China kicks the United States out of Asia and carves out a region of strategic influence, China would pose a further direct threat to the United States. Some may argue that China’s ambitions are not global, but regional, in which case the United States and China could co-exist by peacefully respecting each other’s spheres of influence. However, it is difficult to identify a state’s intentions. Even if we could, intentions can change over time. The United States did not intend to become a global hegemon when it started to rise, but here it is. If China’s ambition is now or later becomes a global hegemon, allowing it to roam freely in the Western Pacific would enhance China’s capability to project power outside the region. Eventually, China may pose a direct threat to the U.S. mainland, and the United States’ global position.

So when we discuss whether the United States should defend or ditch Taiwan, what we should really discuss is whether the United States should seek to maintain its supremacy in the Western Pacific and beyond. Some may think that maintaining U.S. supremacy is a vital interest for the United States, because China would otherwise become an even bigger threat, or because China’s global domination would threaten the rules-based international order, which is also a crucial U.S. interest. Others may argue that it is wiser to give up U.S. supremacy because maintaining it is too risky. Defending Taiwan from China’s aggression would likely generate massive American casualties in light of China’s increasing military prowess. Worse yet, a military clash between the two nuclear weapons states could escalate into a nuclear catastrophe. Ultimately, whether to defend Taiwan or not is a decision our leaders will have to make. When they do, they must understand what is really at stake.

The views expressed are those of the author and do not necessarily reflect the official policy or position of the Department of the Army, Department of Defense, or the U.S. Government.

Lami Kim is an Assistant Professor and Director of Asian Studies Program in the Department of National Security and Strategy at the U.S. Army War College. Her work has appeared in The Washington Quarterly, Global Governance, War on the Rocks, Bulletin of the Atomic Scientists, Belfer Center for Science and International Affairs, the Woodrow Wilson International Center for Scholars, the National Bureau of Asian Research, Routledge, and The Diplomat, among others. She holds a PhD degree from the Fletcher School of Law and Diplomacy at Tufts University and a Master’s degree from Harvard University.