The answer is: One has already failed in Central Europe, and one has kept the peace in East Asia. The question is: Going forward, should America’s deterrence model for Ukraine be the strategic clarity of NATO’s Article 5, or the strategic ambiguity of the 1979 Taiwan Relations Act?

The principle of collective defense is at the heart of NATO, as created by a 1949 treaty. Its history is embedded in WWII, when the Nazis gained a massive advantage in the earliest days of the war by pitting the various European nations against each other and picking off territory as London and Paris bickered over what to do. NATO was to be the solution. Article 5 of the NATO treaty says, “An armed attack against one or more of the [signers] shall be considered an attack against them all and consequently they agree that, if such an armed attack occurs, each of them…will assist the Party or Parties so attacked.”

The critical points are that the treaty is inclusionary—all members, large or small—and exclusionary, in that it only applies to NATO signers. An attack on NATO-member Poland triggers Article 5. An attack on Ukraine or Taiwan, not NATO members, does not.

The 1979 Taiwan Relations Act (TRA) resulted from mainland China dictator Mao’s threat to “liberate” Taiwan and Nationalist dictator Chiang Kai-shek’s demand for U.S. support to reclaim the mainland, which he came close to getting. But with the Korean War sopping up American blood, Washington had little desire to join what would have been a land war in Asia to rival WWII. Instead, the U.S. established diplomatic relations with Taiwan and signed a mutual-defense treaty in 1954.

That lasted until 1979, when the U.S. switched its diplomatic recognition from the people of Taiwan to the people of the mainland (note the TRA’s diplomatic reference to the “people on the China mainland”) and Congress enacted the TRA. The TRA listed two American obligations to Taiwan: to sell it arms and to maintain U.S. capacity “to resist any resort to force or other forms of coercion” against Taiwan.

The wording of the TRA is instructive: “Peace and stability in the area are matters of international concern…any effort to determine the future of Taiwan by other than peaceful means, including by boycotts or embargoes, is considered a threat to the peace and security of the Western Pacific area and of grave concern to the United States.” 

This is diplomatic brilliance, and came to be known as “strategic ambiguity,” a policy understood in context to mean the U.S. doesn’t have to defend Taiwan, but it could. The circumstances and means of defense are left unspoken. China countered with a policy of “strategic patience.” Peace—a stasis, a stalemate; call it what you wish—was the result.

The most important thing about the TRA is that it works. The mainland has not invaded Taiwan. Despite changes in mainland leadership as dramatic as Mao (albeit in 1976) to Deng to Xi, despite Taiwan changing from a military dictatorship to a democracy, the mainland has not invaded. The mainland has not invaded, in spite of several global changes—the direct Chinese-U.S. combat in the Korean and Vietnam wars, China’s development of nuclear weapons, and the fall of the Soviet Union.

The Chinese military grew from peasants with rifles to a blue-water navy, and the nation left its agrarian isolation to become an essential part of the industrialized global economy—and the mainland has not invaded. The U.S. withdrew its troops from Taiwan, and the mainland has not invaded. The U.S. bombed China’s embassy in Belgrade. Ukraine happened. And the mainland has not invaded. There’s a pattern there.

The irony is that deterrence worked in Ukraine—at least from Putin’s point of view. It prevented the U.S. from getting involved in the shooting war between Russia and Ukraine. The NATO treaty only compels its signatories to act once someone moves against one of them (the treaty was written with the Soviet Union in mind; Article 5 has only been invoked once, following 9/11, and then mostly for show).

As Putin readied to invade Ukraine, Biden threw away any trace of strategic ambiguity by declaring early and often that NATO would not intervene and the U.S. would not unilaterally enter the fighting. It was as green a light as Putin could hope for, but consistent with the fully defensive nature of the NATO treaty. On the other side of the world, Sino-Asia sleeps at peace knowing everything is on the table should the mainland invade, but nothing is at risk should it not. Is there a better definition of deterrence?

The concern now is moves in both hemispheres to formalize new, explosive redlines. Much talk will be devoted to whether Ukraine should join NATO, feign interest in joining NATO, or promise never to join NATO. Ukraine’s joining NATO or something similar would be the wrong answer. It was, in fact, the rigidity of NATO’s promise that saw it fail again in Ukraine as it did in Crimea.

Putin, judo master that he is, understands this, and uses it against his adversaries. NATO prescribes war whether or not the broader circumstances (say, the prospect of being dependent on Russian gas) make war seem wise. It is an exploitable flaw. The good news is that Europe, for the time being, is again at a stasis point. Ukraine is seemingly headed toward a resolution, spoken or not, that provides Russia its buffer zone no matter Western-media spin about who won and lost. An ending in which everyone declares victory— with Russia holding the Donbas and greater Ukraine free from the invaders—is never a bad thing.

The risk lies in Asia, where bullish elements are tempted to disturb a functional status quo. Plus, there’s Joe “Regime Change” Biden and his gaffes again. At a CNN town hall in October 2021, the host asked Biden if the U.S. would defend Taiwan. “Yes, we have a commitment to do that,” he said—another gaffe-erino that the White House quickly walked back into the realm of strategic ambiguity.

But post-Ukraine, some hawks want clarity and are pushing for a formal, Article 5-like declaration. In the hawks’ perfect world, that “Asian Article 5” would include not only Taiwan and the U.S., but also Japan, Korea, Australia, the Philippines, and maybe others (of course, the U.S. already has various types of self-defense treaties already with many Asian nations, including the recently adopted semi-formal Quad dialogue group, which includes India).

The justifications offered for such moves often make no sense given the multi-decade success of the current TRA strategy. Some say that since Beijing ramped up its rhetoric and shipbuilding (a test of resolve!), we need to do something to match them. But wouldn’t a guarantee to go to war for Taiwan make those in Taiwan who want to declare formal independence that much more reckless? 

There are those in Congress who want a more formal agreement (if you think the Israel lobby is powerful, check how Taiwan punches above its weight). The ever-pugilistic Council on Foreign Relations wants strategic un-ambiguity as a show of force.

Joe Biden will come under pressure to “do something” (the scariest words in Washington) following his failure in Ukraine. This would be a very, very risky move. Remember—credible deterrence does not need to involve being willing to commit national suicide in the face of a challenge, but must still carry the possibility that the deterrent is likely to do something that is “fraught with the danger of war.”

Strategic ambiguity is enough. Article 5 and anything like it to come in the Pacific ties signatories’ hands. The Taiwan Relations Act instead leaves all options open to deal with the complex realities of the Sino-Pacific. History shows which approach works and which does not. A more aggressive posture does not resolve the root issues across the Taiwan Strait, it only risks exacerbating them. TRA is a model for a future agreement with Ukraine.

Peter Van Buren is the author of We Meant Well: How I Helped Lose the Battle for the Hearts and Minds of the Iraqi People, Hooper’s War: A Novel of WWII Japan, and Ghosts of Tom Joad: A Story of the 99 Percent.