Why Ukraine wants a no-fly zone — but is unlikely to get one

• The U.S. and other major powers have so far ruled out establishing a NFZ over Ukraine.

No-fly zones explained

• A no-fly zone is airspace where certain aircraft are not allowed to enter.
• In the context of conflicts and wars, it is typically used to stop banned aircraft from entering airspace to launch attacks, transport troops and weapons, and conduct surveillance.
• No-fly zones must be enforced militarily, which can include shooting down banned aircraft.

What Ukraine wants

• Zelensky has made near-daily calls for a no-fly zone over "significant parts" of Ukraine.
• "If the West does this, Ukraine will defeat the aggressor with much less blood," Zelensky told Axios earlier this month.
• He repeated that call in a virtual address to Congress on Wednesday but acknowledged it is a red line for the U.S. He asked for surface-to-air missile systems as an alternative so that the Ukrainian army can target Russian bombers.

Why the West is unlikely to act

• If Western countries, specifically NATO, impose a no-fly zone, they would be responsible for enforcing it, which could mean bringing down banned Russian military planes.
• "If NATO imposes it, and we shoot down even one Russian plane, we're at war with Russia," says Howard Stoffer, a professor at the University of New Haven. That would be a major escalation and is not something NATO wants to do at this point, Stoffer tells Axios.
• Unlike past conflicts in which NFZs have been enforced, Russia has a robust and highly sophisticated military and is a nuclear power.

There are also major logistical hurdles, says Stoffer, who served in the State Department for more than two decades.

• Not only would NATO need to decide which countries would be responsible for it, the alliance would also have to set up a "very complicated" defense system for monitoring and enforcing it.

What the West says

• President Biden and the White House have repeatedly said the U.S. will not send American troops to fight Russia in Ukraine, including to enforce a NFZ.
• "It would require, essentially, the U.S. military shooting down Russian planes and causing ... a potential direct war with Russia — something we want to avoid," White House press secretary Jen Psaki has said.
• NATO Secretary-General Jens Stoltenberg has also ruled out NFZs, saying: "We understand the desperation but we also believe that if we did that (impose a no-fly zone) we would end up with something that could lead to a full-fledged war in Europe involving [many] more countries and much more suffering."
• “We are not part of this conflict, and we have a responsibility to ensure it does not escalate and spread beyond Ukraine,” he added.

What Russia says

• Russian President Vladimir Putin has said that Moscow will consider a declaration of Ukraine as a no-fly zone by any third-party as "participation in the armed conflict."

• "That very second, we will view them as participants of the military conflict, and it would not matter what members they are," Putin said.

Where NFZs have been used

• Libya: The UN Security Council authorized a no-fly zone, enforced by NATO, over Libya in 2011 to "protect civilians under threat of attack in the country."
• Bosnia: NATO enforced a no-fly zone over Bosnia from April 1993 to December 1995.
• Iraq: The U.S. and coalition countries imposed two no-fly zones in Iraq after the 1991 Gulf War.
• Yes, but: The militaries of the U.S. and other countries enforcing the NFZs were vastly superior to those they faced in these cases.

The bottom line

• Imposing a no fly zone is "a premature idea right now," says Stoffer.
• "We are not in a position where we want to get engaged in conventional conflict with the Russians because that could rapidly escalate to a tactical nuclear level and a strategic nuclear level," he adds. "Then we're dealing with the end of history as we know it."

Go deeper:

• Axios explains Ukraine
• The latest on the Russia-Ukraine crisis
• Zelensky: If West won't impose no-fly zone, "give me the planes"

Editor's note: This story has been updated with additional details from Zelensky and Putin.