How No-fly Zones Work

By: Patrick J. Kiger  | 
Ukrainian-Americans in New York City gathered to protest the Russian invasion of Ukraine and to demand a no-fly zone be established. Andrew Lichtenstein/Corbis via Getty Images

After Russia invaded Ukraine in February 2022, Russian airstrikes began devastating Ukraine's cities, killing scores of civilians in the process. That led Ukrainian President Volodymyr Zelensky to call upon the U.S. and its NATO allies, who already were supplying Ukrainian defenders with both Stinger and Patriot missiles and other assistance, to go a step further. Zelensky repeatedly called upon them to use their air forces to prevent Russian aircraft from entering Ukraine's airspace.

"We repeat every day: 'close the sky over Ukraine!'" Zelensky implored in a video. "Close for all Russian missiles, Russian combat aircraft, for all these terrorists. Make a humanitarian air zone."


What Zelensky sought is something called a no-fly zone, known in global security lingo as an NFZ, a concept invented in the early 1990s. In a no-fly zone, a military power or alliance stops an attack on another nation by making its airspace off-limits to the aggressor.

A no-fly zone doesn't necessarily have to cover an entire country. Instead, it might only cover a portion where the fighting is occurring. But either way, a no-fly zone must be enforced by the threat of force. The nation or nations imposing the no-fly zone must deploy surveillance aircraft to monitor the airspace, as well as fighters to deter — and if necessary — shoot down any hostile aircraft that enter the space.

Additionally, creating an effective no-fly zone may also require destroying or disabling any ground-based anti-aircraft systems that the aggressor country possesses, so that they can't be used to attack the aircraft enforcing the ban [sources: Brooke-Holland and Butchard; Ramzy].

No-fly zones have only been utilized three times in history — in parts of Iraq, following the 1991 Gulf War; in Bosnia in 1992; and Libya in 2011 [source: Brooke-Holland and Butchard]. Those crises were situations in which the U.S. and NATO used their superior air power to stymie authoritarian rulers of less powerful countries from brutally suppressing rebellions and terrorizing civilian populations.

But in Ukraine, the U.S. and NATO have so far resisted imposing a no-fly zone out of concerns that it would draw them into an armed showdown with Russia, whose increasingly irrational leader, Vladimir Putin, might resort to using nuclear weapons [source: CNN].

In this article, we'll look at what it requires to impose a no-fly zone, and whether no-fly zones are effective at their intended goal. But first, let's discuss when, where and why no-fly zones are needed.


The Origins of the No-fly Zone

no-fly zone Iraq
In 1991, the no-fly zone in Iraq was part of the cease-fire agreement ending the Gulf War of 1990-1991. Initially it involved only the northern line at the 36th parallel. A southern no-fly zone was created in 1992 and was extended to the 33rd to protect Shiite Muslims in the southern areas from Iraqi fighter aircraft. U.S. Air Force

In spring 1991, the United States and allies expelled Iraqi dictator Saddam Hussein's forces from neighboring Kuwait. Iraq's long-oppressed Kurdish minority, encouraged by American radio broadcasts, staged a revolt in northern Iraq.

In response, Saddam sent helicopter gunships armed with napalm and chemical weapons to rout the rebels. Hundreds of thousands of Kurdish civilians fled the brutal onslaught, and became trapped on barren hillsides near the Turkish border without food or water. U.S. President George H.W. Bush and his European allies found themselves in an agonizing situation. They were reluctant to remove Saddam from power, but didn't want to see a humanitarian disaster they'd inadvertently instigated [source:].


Instead, they hit upon a solution. In April 1991, the U.N. passed another resolution condemning Hussein's repression of the Kurds and called upon member nations to assist in relief efforts. U.S., British and French air forces moved in and launched a massive supply and rescue operation. The resolution warned Hussein not to interfere with relief efforts, and the allies used that authority to declare what may have been the first no-fly zone in history — a 19,000-square-mile (49,209-square-kilometer) area north of the 36th parallel.

In 1992, a second no-fly zone was imposed south of the 33rd parallel, to protect Shi'ite Muslims who had also rebelled. When Saddam violated the no-fly zones, the coalition forces punished those infractions with force — either by shooting down Iraqi regime aircraft, or by destroying Iraqi military targets with missiles. The ban continued until the United States invaded Iraq to overthrow Saddam in 2003 [source: BBC News].

The breakup of Yugoslavia in the early 1990s, and the bloodshed that resulted, led NATO forces to impose another U.N.-authorized no-fly zone in 1993 over the breakaway region of Bosnia and Herzegovina. Operation Deny Flight was intended to block Bosnian Serbs, who controlled virtually all the military aircraft in the region, from attacking their Muslim neighbors from the air. The mission later was expanded, and NATO attacked Bosnian Serb anti-aircraft missile installations, artillery and armor in an effort to compel them to stop their aggression [source: Keating,].

After a popular rebellion erupted against Libyan dictator Muammar Gaddafi in the spring of 2011, the U.N. Security Council passed resolution 1973, which banned all flights in Libyan airspace and authorized U.N. members to act individually or as a group to take "all necessary measures" to protect Libyan civilians [source:].


How No-fly Zones Are Created

no-fly zone Libya
In March 2011, NATO took over full command of military operations from a U.S.-led coalition to enforce a no-fly zone in Libya. ARIS MESSINIS/AFP via Getty Images

Because the concept of no-fly zones has been around for only about 30 years, and has been utilized only three times, there isn't yet a standard playbook for how they are to be set up and enforced.

For one thing, there's the question of where the U.S. or NATO gets the legal authority to impose a no-fly zone. One source of justification could be Chapter 7, Article 42 of the U.N. Charter, which states that if diplomacy isn't able to resolve a threat to international peace, the U.N. may authorize "demonstrations, blockade, and other operations by air, sea or land forces" [source:].


Thus, the first step to establishing a no-fly zone is to obtain a mandate from the 15-member U.N. Security Council. That usually requires some deft diplomacy, since any of the five permanent members — the United States, China, Russia, the U.K. and France — can block the action with a veto.

In the case of the Libyan no-fly zone, China and Russia opposed the plan but were persuaded by advocates to abstain from the vote [source:]. In Ukraine, though, that source of authority isn't available, because Russia, which has a permanent seat on the U.N. Security Council, most likely would block any no-fly zone resolution.

However, according to a research briefing released by the U.K. Parliament March 7, 2022, a no-fly resolution also can be established with the consent of the state whose airspace it protects. That would enable the elected government of Ukraine to authorize NATO to close off access to its airspace [source: Brooke-Holland and Butchard].

Once authority is established, there's also the question of what specific conditions should be imposed. In Libya in 2011, for example, the U.N. resolution laid out only the most basic parameters. It banned any flights in Libyan airspace, except for humanitarian missions to deliver medical supplies and food, or to evacuate foreign nationals from the conflict area. It also authorized member states to enforce the ban, provided that they notify the U.N. and report back on a monthly basis to detail their actions and provide information on any violations of the ban.

United Nations member were also authorized to deny permission to any aircraft to take off from, land in or overfly their own airspace, if they had reason to suspect that a plane is transporting weapons or mercenaries to Libya [source:].

One reason that imposing no-fly zones is so complicated is that the U.N. and the countries who'll provide aircraft, missiles and personnel have to agree on rules of engagement (RoEs), which spell out, among other things, when and how to confront possible violators, how much force can be used against them, and who authorizes taking action in such situations. We'll discuss the RoEs for no-fly zones and how they're carried out next.


How to Keep Aircraft Out of the Sky

U.S. Air Force F-16
Aircraft must patrol no-fly zones to keep enemies from entering the space. Here a U.S. Air Force F-16 is seen patrolling the no-fly zone in Northern Iraq. U.S. Air Force/Getty Images

Exactly which measures an international coalition takes to enforce a no-fly zone seems to vary quite a bit.

In Iraq, for example, coalition air forces operated under fairly restrictive rules of engagement so that they were forced to play cat-and-mouse with violators and only whittle away gradually at Iraqi anti-aircraft defenses. In Libya, in contrast, the U.N.'s broad authorization of "all necessary measures" gave NATO a lot of leeway [source: Robinson].


As a result, the first step in Operation Odyssey Dawn, as the 2011 Libyan mission was dubbed, was not a patrol, but an attack. On day one, U.S. Navy ships and a British unleashed a barrage of 112 Tomahawk cruise missiles on 20 Libyan military targets, crippling Gaddafi's radar, command-and-control infrastructure and anti-aircraft missile installations. The goal was to "shape" the battle space to reduce the risk to NATO pilots who eventually would patrol it [source: Robinson, Knickerbocker].

After high-altitude U.S. pilotless, drone surveillance aircraft were sent in to assess the first day's damage, U.S. Navy radar-jamming aircraft began flying over Libya as an added measure to neutralize what remained of Gaddafi's air defenses and to prevent his small air force of aging 1960s-vintage fighter jets from getting into the air. At the same time, aircraft from the United States and other NATO forces began to pound Libyan military targets, with the aim of further reducing his ability to attack rebels and civilians [source: Robinson, Knickerbocker].

The air crews who patrolled Libyan airspace had a complicated job. According to a 2011 NATO article, the crews spent about four hours being briefed about the latest intelligence, studying weather data and the positions of other coalition aircraft, and preparing and checking their equipment and plane before taking to the sky. Once in the air, they received a second intelligence update from surveillance aircraft, and then cruised around the area, watching for any planes to enter the no-fly zone. If one was spotted, they had to determine whether it was a "hostile" aircraft, or one that had simply entered the airspace by mistake. Before taking any action against the intruder, they generally had to obtain clearance from a commander on the ground [source: Booth].

In Ukraine, establishing a no-fly zone would be vastly more complicated, because of the risk of a confrontation with Russia. A March 4, 2022, article by the German Marshall Fund advocated a less-stringent alternative version, in which three countries bordering Ukraine — Poland, Slovakia and Romania — might declare 62-mile (100-kilometer) wide zone from their borders to be a humanitarian zone, which would allow Ukrainian refugees to flee without threat of being attacked by the Russians.

NATO, which would enforce the limited no-fly zone, would establish rules of engagement in which its warplanes wouldn't automatically shoot at Russian aircraft, but would instead intercept them or disrupt their movements with approaches and close passes [source: Hegedus]. An open letter led by Robert McConnell, co-founder of the U.S.-Ukraine Foundation and signed by 27 former national security officials and scholars, advocated such an approach.

That alternative, however, wouldn't protect Ukraine's cities from attack by the Russians, and Ukrainians who didn't want to become refugees would still remain vulnerable.


How Well Do No-fly Zones Work?

F-35A Lightning II aircraft
U.S. Air Force and Royal Netherlands Air Force F-35A Lightning II aircraft conduct a bilateral air-to-air training exercise over the Netherlands Feb. 22, 2022. Whether these planes would be called to patrol Ukrainian airspace is still unknown. Tech. Sgt. Rachel Maxwell/Air Force

Enforcing the Libyan flight ban over an extended period was a major challenge for NATO, since Libya covers 680,000 square miles (1,761,191 square kilometers). On the plus side, most of the population lived on 10 percent of the land, in a narrow region along the coast [source: France24]. A March 2011 analysis by the Center for Strategic and Budgetary Assessments estimated the cost of imposing a no-fly zone over the entire country for a six-month period at $3.1 billion to $8.8 billion [source: Harrison and Cooper].

Additionally, no-fly zones necessitate risks to NATO pilots. In Bosnia in 1995, U.S. Air Force Capt. Scott O'Grady's F-16 was hit by a surface-to-air missile. Grady was forced to eject and parachute into Serbian-held territory. Relying upon his survival training, he spent six harrowing days evading Bosnian Serb pursuers, eating ants and catching rain in a plastic bag for drinking water. Fortunately, he was able to establish radio contact with a U.S. search plane, and eventually was rescued by a team of Marines [source: Fedarko].


In Iraq, Saddam Hussein reportedly offered a $14,000 reward in the late 1990s to anyone who could shoot down a coalition aircraft, but fortunately no one ever was able to collect [source: Correll]. Even in Libya, where anti-aircraft defenses had been been destroyed, NATO airplanes still faced the threat of shoulder-fired missiles.

Imposing a no-fly zone in Ukraine also would entail even greater risks than in the past. NATO pilots would be vulnerable to attack not just from Russian ground forces and aircraft within Ukraine, but by S-400 surface-to-air missiles launched from inside Russia itself, unless those systems were destroyed [source: Nevitt]. That would require escalating the conflict to a very dangerous level.

Critics of no-fly zones also question whether they actually achieve their intended purpose of preventing despotic regimes from killing their own people. In Bosnia, for example, the no-fly zone failed to prevent Bosnian Serb forces from laying siege to Srebrenica and massacring 7,000 Bosnian Muslim men and boys there in 1995 [source: BBC News].

It's hard to find research data showing the effectiveness of no-fly zones in reducing civilian casualties. Critics have argued that their impact is limited, because no-fly zones focus upon eliminating threats from the air, but don't stop ground-based attacks. In Iraq and Bosnia, for example, Saddam Hussein and the Serbs both shifted to tanks, artillery and infantry to continue the killing [source: Renner, Benitez and Pietrucha]. To completely stop such violence, it might be necessary to augment a no-fly zone with ground troops.

Even so, agonizing images from Ukraine of apartment buildings and hospitals demolished by airstrikes, and bloodied civilian survivors crying out in anguish over the loss of life, form a powerful argument in favor of a no-fly zone that dispassionate analysis can't totally refute.

As Ukrainian President Zelensky recently chided NATO countries, saying that if they didn't impose a no-fly zone or give the Ukrainians aircraft to protect themselves, there can be only one conclusion: You want us to be slowly killed" [source: Saric].


Frequently Answered Questions

Why do Ukraine want a no-fly zone?
The Ukrainian government has requested a no-fly zone in order to prevent further Russian aggression.

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More Great Links

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