Faced with a brutal Russian invasion of Ukraine, many Americans and Europeans are pushing for their governments to provide as much military support as possible to Kyiv. One idea that a number of prominent observers and commentators have seized on is the establishment of a no-fly zone—that is, using force (or the threat of force) to keep Russian aircraft out of some segment of the airspace above Ukraine, in order to prevent Russian air strikes on Ukrainian military forces and civilians in the area. Creating such a zone would involve a combination of day-to-day intelligence collection, observations from the ground, rotating aerial patrols with large numbers of planes and pilots—and, crucially, the threat to physically prevent adversary aircraft from entering the designated airspace.

Proposals for a no-fly zone are inspired by the concept's application by U.S. and NATO forces in Iraq after the Persian Gulf War, in Bosnia in the mid-1990s, and in Libya during its civil war in 2011. Notably, those cases did not involve imposing an exclusion zone on a major power; instead, they featured a mighty great power, the United States, dictating demands to weak local adversaries that were in no position to contest them. There are no examples of something called a “no-fly zone” being imposed on a major power outside the context of battles for air superiority in regular warfare.

The idea of establishing a no-fly zone reflects a humane urge to relieve Ukrainian suffering and to "do something" in the face of Russian aggression. But doing so would risk stumbling into a far worse tragedy. This applies even to a limited no-fly zone of the kind floated earlier this week by more than two dozen experts and former officials—an idea that may sound reasonable but is in fact profoundly reckless.


The idea of a limited no-fly zone aims primarily to protect corridors through which civilians can escape, safe from Russian air strikes. But in the first couple of weeks of war, at least, Russian air operations have not been the main problem. Artillery and missiles fired from the ground have done far more damage than Russian bombers, and a no-fly zone would have little effect on such attacks.

And even if one accepts the premise that restricting Russia’s access to Ukrainian airspace would make a significant difference, proposals for a no-fly zone for Ukraine still suffer from one of two crucial mistakes: either they assume a best-case result in which the Russians simply cooperate with the demand, or they accept a significant risk of provoking a war directly between NATO and Russia.

It is possible that Russia would be prudent and simply accept a demand to stand down from operations in and around corridors set aside for the evacuation of civilians. But that is hardly probable: after all, Moscow has already gambled on a war that it claims was motivated in the first place by a threat from NATO, the war’s earliest phase has produced embarrassing results for the Russian military, and Russian President Vladimir Putin is unlikely to do anything that might look like a retreat in the face of a NATO ultimatum.

Establishing a no-fly zone risks stumbling into a far worse tragedy.

If the Russians did not accede to a no-fly zone, NATO would have to decide whether to enforce it, which would mean being ready to shoot down Russian planes—and firing the first shots, at that. Make no mistake: whether or not air combat to enforce the zone would remain limited to Ukrainian airspace, it would amount to initiating war between NATO and Russia. And even limited conflict would be epochal: it would be the first direct war between major powers since 1945.

Of course, the United States and its allies are already involved in combat against Russian forces, but only indirectly, by providing weapons and supplies to Ukraine. Such involvement, however, remains below a threshold for escalation that has been tacitly established by past experience.  For example, the Soviets supplied the North Koreans and the Chinese in their war against Americans in Korea in the 1950s, and again supplied the Vietnamese communists against Americans in the 1960s. For its part, the United States supplied the mujahideen fighting the Soviets in Afghanistan in the 1980s.  In these cases, the Russians and the Americans were angered by the toll such assistance took but refrained from retaliating with force against the suppliers, lest the small wars metastasize into huge ones. It is true that U.S. and Soviet pilots engaged each other directly in some aerial combat during the Korean War. But both sides kept this strictly secret until many years later, precisely to restrain political pressures to expand the war. In today’s world of technologically promiscuous communication and abundant open-source intelligence, there is no way aerial combat over Ukraine would remain secret.

Additionally, the outbreak of a great-power war is not the only risk posed by declaring a no-fly zone. Consider what might happen if the Russians refused to accept the no-fly zone and, in the face of Moscow’s intransigence, NATO backed down and decided to not enforce it, after all—precisely to avoid a wider war. The declaration of a no-fly zone would be exposed as a pathetic bluff—little more than a no-fly request. Although the importance of credibility is often exaggerated and too often used as an excuse for mistaken military commitments, in this case the damage to NATO’s credibility would be tremendous. Such a move would not just reveal the emptiness of posturing to help Ukraine but would also highlight and intensify doubts about whether the alliance would make good on its foundational promise of collective defense, especially when it comes to weaker, newer members, such as the highly vulnerable Baltic states.


The war in Ukraine is the agonizing outcome of Putin’s outrageous response to two errors on NATO’s part. The first of these was the alliance’s declaration, in 2008, that Ukraine and Georgia would one day join it. (In Ukraine’s case, a scheme for the country’s Finlandization would have been better, exchanging its neutrality in relations between Moscow and the West for the country’s independence and internal democracy.) Once the goal of NATO membership was declared, however, the second mistake was not accomplishing it right away and thus immediately establishing NATO’s deterrent guarantee. Given Putin’s view of NATO enlargement as a threat to Russia, this period of ambiguity created an incentive—and an opportunity—for him to carry out a preventive war.

The resulting tragedy is heartbreaking. But trying to cope with it by belatedly entering the war directly—desperately endorsing a no-fly zone with no assurance it would not lead to a bigger disaster—would only compound the tragedy. NATO should help Ukraine, but its assistance must remain below the established threshold for escalation. That would include more or less what the alliance has already been doing: where possible, providing relief for civilian refugees and weapons, ammunition, food, and logistical support to Ukraine’s military.

The urge to help Ukraine is laudable. But the only things worse than watching the country’s slow-motion defeat would be to promise direct military intervention and then fail to follow through or, worse, to up the ante and turn what is now clearly a new cold war into a hot war—one that could produce destruction and casualties in the wider world on a scale that would make even the devastation of the current war in Ukraine seem insignificant.

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