‘Strategic Ambiguity’ Has the U.S. and Taiwan Trapped

As the United States settled into the winter holiday season, China dispatched 71 aircraft for military maneuvers around Taiwan, its largest single incursion ever. The incident came on top of hundreds of flights over the past 18 months as well as military exercises and missile launches near the main island in the wake of then-U.S. House Speaker Nancy Pelosi’s visit in August last year. Alongside warnings of further military reprisals, Beijing has also increased its nuclear warhead stockpile, deployed a hypersonic glide vehicle, launched a third aircraft carrier, and further modernized its military.

Meanwhile, the United States continues to debate how best to maintain the status quo in the region, support the self-ruled island, and deter a Chinese attack. Washington’s current policy is one of “strategic ambiguity”—based on the theory that it’s best to keep all parties guessing whether, and to what extent, the U.S. military will intervene in a war across the Taiwan Strait. Is that still the appropriate strategy to deter Beijing? Or should Washington publicly commit to Taiwan’s defense, as former NATO Secretary-General Anders Fogh Rasmussen urged on Jan. 5?

Strategic ambiguity typically is understood as deliberately creating uncertainty in Beijing and Taipei about whether the United States would intervene in a war. This supposedly creates dual deterrence: The threat of U.S. intervention prevents China from invading, and the fear of U.S. abandonment prevents Taiwan from sparking a war by declaring independence, which China considers a casus belli. This approach, supporters contend, has kept peace for decades and prevented entrapment, whereby the United States unwillingly gets pulled into war.

Strategic ambiguity, however, may rest on faulty concepts and little systematic evidence. The United States has never officially articulated what it means nor adopted it as policy. At this point, strategic ambiguity may be doing more harm than good. And there are good arguments that Washington might consider switching to a policy of strategic clarity—such as a NATO-style security guarantee for Taiwan—instead.

Washington wants Taipei to increase defense spending and implement its porcupine strategy before making further, unspecified commitments.Political science considers strategic ambiguity a form of pivotal deterrence, where one state prevents two others from going to war against each other. But this only works under three conditions. First, the pivot (the United States, in this case) must possess decisive military power over the adversaries (China and Taiwan). Second, both adversaries must want war more than the pivot does. (Otherwise, the pivot should simply line up with its preferred partner.) Finally, neither adversary can be irrationally committed to going to war. When all three conditions hold, the pivot can swing its decisive power against whichever country is upsetting the status quo. Because it doesn’t commit to any particular course of action, both adversaries are unsure about the U.S. reaction and therefore avoid escalation.

Across the Taiwan Strait today, the first two of these conditions no longer hold. The Chinese military budget has  increased fivefold since 2001, and it now fields the world’s largest missile force, the second-largest navy, and the third-largest air force. According to a Rand Corporation report, in 2017, China already possessed parity with or even an advantage over U.S. forces in five of nine operational areas involved in a Taiwan scenario. In deterrence theory, the United States is no longer a pivot.

Beijing’s rising power also deters Taiwanese adventurism. Taipei doesn’t want a war because it knows that it will be the first to suffer Beijing’s retaliation. No major Taiwanese politician has advocated declaring independence from China since 2005. In any event, Taiwan’s president has no constitutional authority to unilaterally declare independence, and solid majorities consistently favor maintaining the status quo for fear of a military reprisal.

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As Beijing’s military capabilities have increased, pivotal deterrence has steadily faltered—exactly as the theory predicts. In 1996, Beijing fired missiles over the island to protest the Taiwanese president speaking at his college reunion in the United States. But it avoided further provocation after Washington sailed two aircraft carriers through the strait. After Pelosi’s 2022 trip to Taiwan, China responded with military exercises and missile overflights. Washington restricted itself to verbal condemnation and avoided any military displays, even as the Chinese People’s Liberation Army has continued its coercion and incursions.

Despite this, proponents cling to strategic ambiguity in large part because they worry that an unconditional security guarantee would enable Taiwan to entrap the United States into going to war against China.

But entrapment almost never happens. One scholar found only five possible instances since 1945, and in only of them—Vietnam—was the United States dragged into war. Countries wriggle out of alliance promises by attaching conditions, taking advantage of ambiguity, employing legal language tricks, or simply walking away. Washington could put guardrails on any defense promises, such as mandatory crisis consultation and nullification if Taiwan declares independence. Even NATO’s supposedly ironclad mutual security guarantee is implemented “in accordance with [each country’s] respective constitutional processes,” language specifically inserted by U.S. negotiators. If the United States can avoid entrapment by NATO, then it likely can avoid it by Taiwan.

Further, strategic ambiguity is largely irrelevant to whether China decides to attack Taiwan. China “has already priced in a full U.S. defense,” U.S. Sen. Chris Murphy tweeted. Its operational plans assume Washington will intervene. U.S. and allied power—not ambiguity—is what deters China. Ambiguity by itself offers little additional benefit.

Strategic ambiguity seems to have snared the United States and Taiwan in a prisoner’s dilemma.

That means that if anything is likely to deter Chinese aggression, it is further improvements to Taiwan’s security. Strategic ambiguity could cause more harm than good on this front as well.

As I’ve written, U.S. intervention is essential to defeating a Chinese invasion of Taiwan. Taipei must ensure that the United States shows up, and arms sales are the clearest and strongest indication of U.S. support. Taipei purchases high-end weapons systems, believing that Washington’s willingness to sell these platforms raises the likelihood that it will step in to defend the island.

However, analysts agree that Taiwan’s best strategy is an asymmetric, porcupine defense, which is embodied in a Taiwanese military plan called the Overall Defense Concept. The island would bristle with mines and anti-ship, anti-air, and anti-vehicle missiles, buying time for the U.S. military to arrive. However, high-end equipment like F-16 aircraft, heavy tanks, and submarines are useless for this mission; they are likely to be destroyed in any invasion’s opening salvo. But Taipei cannot fully switch to asymmetric defense because strategic ambiguity leaves it uncertain whether Washington will intervene.

This creates a U.S. problem in Taiwanese politics. Former Taiwanese President Ma Ying-jeou stated, “The Americans … will sell us weapons and provide us with intelligence, but they won’t send troops.” Kuomintang, his political party, is skeptical of Washington’s intentions, prompting some members to advocate greater autonomy in Taiwan’s defense decisions. Other experts go so far as to suggest accommodating China. This attitude shouldn’t come as a surprise. Military alliances allow small states to resist overwhelming threats. Without them, countries tend to bandwagon with their threatener to avoid a hopeless war.

If this were to happen in Taiwan, Washington would lose a critical partner in strategic competition with China. Beijing could use Taiwan as an “unsinkable aircraft carrier” to project power into the Pacific, choke off U.S. support to Japan and South Korea, dominate the Philippines, and further consolidate control over the South China Sea.

Strategic ambiguity seems to have snared the United States and Taiwan in a prisoner’s dilemma. Washington wants Taipei to increase defense spending and implement its porcupine strategy before making further, unspecified commitments. Taiwan spends a larger proportion of its government budget on defense than even the United States, but it wants to receive the U.S. commitment its defense concept depends on before further implementation. The Taiwanese will to fight increases significantly if Washington intervenes. Each side’s strategy hinges on the other’s actions, and each side is stuck waiting while China continues modernizing its military.

Strategic clarity may offer a way out of this dilemma. Of course, any shift would have to be implemented carefully, with military preparations in place before any public announcement of a U.S. commitment. But as the weaker, threatened party, Taiwan runs much greater risks from closing the door on accommodating China; it would need private, concrete assurances that these risks would be rewarded. These, of course, would have to be tied to clear markers that Taipei is actually implementing its existing defense strategy.

Strategic clarity might offer the best chance for a superior Taiwanese force posture that is aligned with the United States’ defense strategy. Moreover, as Taipei enhances its asymmetric defenses, the need for U.S. intervention decreases. Ukraine’s successful fight against Russia’s invasion demonstrates how the right weapons, paired to an effective strategy, can defeat a seemingly overwhelming force—all at relatively little cost to the United States and other NATO allies. Strategic clarity would resolve the political obstacles currently preventing Taiwan from adopting a similar posture. Clarity would advance U.S. interests by improving Taiwan’s defense, lowering the risk of a wider war, and containing China.

For its proponents, the idea of strategic ambiguity seems to have become an end in itself that has not, and logically cannot, adapt to the disruptive growth in Beijing’s military power. The conditions under which the policy worked seem to have evaporated with China’s rise.

This article appears in the Spring 2023 print issue of Foreign Policy magazine. Subscribe now to support our journalism.