What is it?

As the name suggests, a no-fly zone is a geographical area designated as forbidden to air traffic, and is instituted as a way of preventing rogue regimes from bombing their own people. In order to be effective, a no-fly zone must be patrolled by military aircraft that have the authority to shoot down unauthorized planes.

The first job of a force that's been put together to maintain a no-fly zone is to knock out the rogue regime's air force — which should be a fairly easy task in a case like Libya. It's believed that while the Libyan air force is the largest in north Africa, it has decayed significantly since the mid-1970s, consisting primarily of aging bombers.

Libya's air force was reduced by two jets on Feb. 21, 2011, when two Libyan pilots landed their fighters in Malta and asked for asylum. (Lino Arrigo Azzopardi/Associated Press)

Addressing a possible deployment in Libya, U.S. Secretary of Defence Robert Gates said that establishing a no-fly zone first requires knocking out Libyan radar and anti-aircraft missile capabilities. It also means disabling enemy aircraft and runways.

With its air force crippled, pro-Gadhafi forces would have to rely on ground troops for further military action. The coalition enforcing the no-fly zone would then focus their efforts on preventing ground troops from moving against anti-Gadhafi protesters.

In order to keep the air patrol constant, military forces must have air bases and tankers nearby for staging and refuelling purposes. Depending on the number of support stations available, NATO or the U.S. may ask some of its regional partners for permission to use their airfields.

Who decides on the creation of a no-fly zone?

Because it is essentially an act of aggression, a no-fly zone should ideally meet a consensus and abide by the standards of international law. It is typically imposed through a UN resolution, but not always. In 1999, NATO moved ahead without UN authorization to impose a no-fly zone in Kosovo, in order to launch an air assault on Serbian forces.

On Mar. 17, the UN Security Council approved a resolution implementing a no-fly zone over Libya, authorizing "all necessary measures" to stop attacks on civilians — including strikes by sea and air — hours after Libyan dictator Moammar Gadhafi vowed to launch a final assault and crush the weeks-old rebellion against him.

(CBC)

What might a no-fly zone in Libya look like?

The no-fly zone in Libya would likely be concentrated in the northern two-thirds of the country, which includes the capital Tripoli and rebel stronghold Benghazi. The lower third of the country is considerably less populated. Nearly all of Libya's military and air force bases would fall within the hypothetical boundary, with the exception of Ghat airforce base.

Canada has committed six CF-18 fighter jets with support from 140 air crew from CFB Bagotville to help enforce the no-fly zone. Britain and France have indicated that they will also provide aircraft to the mission.

The U.S. has already moored two warships off Libya, with a combined 800 Marines aboard, and has two aircraft carriers in the area with another mobilized recently from Virginia. There are American military bases in Spain, Italy and Turkey, as well as forces in African regions south of the Suez Canal. Although there has been talk of using nearby Malta as a possible NATO base, Maltese Prime Minister Lawrence Gonzi has said his country’s involvement in Libya would be strictly humanitarian; he would not host NATO forces.

What role do AWACS planes play?

An AWACS plane has powerful surveillance capabilities, including a mounted radar dome. Yuriko Nakao / Reuters

In the absence of ground-based radar, NATO operates a series of Boeing E-3A Sentry aircraft known as Airborne Warning & Control System (AWACS) planes, which are invaluable in maintaining a no-fly zone. With powerful sensors in a mounted radar dome as well as on the fuselage and wings, these aircraft have 360-degree surveillance coverage.

According to NATO, one AWACS aircraft flying at 30,000 feet has a surveillance area coverage of over 312,000 square kilometers, while three AWACS flying in a coordinated orbit can cover the whole of Central Europe.

What are the risks of imposing a no-fly zone?

Enforcing a no-fly zone is not a passive act, but a military intervention. As such, it is quite likely to anger the regime in question. In the absence of air assaults, the government in question could choose to step up its ground attacks against civilian populations.

As previously mentioned, enforcing a no-fly zone often requires air strikes, which could imperil innocent civilians. Military experts also caution that establishing a no-fly zone can easily lead to a deeper engagement, if not full-on participation in a war. After the first Gulf War, two no-fly zones over Iraq remained for over a decade, and only ended with the launch of full-scale invasions.

What are some recent examples?

Iraq: Following the end of the first Gulf War in 1991, Allied forces from the U.S., Britain and France maintained two no-fly zones in Iraq — one in the north and one in the south. (The middle of the country was not under such restrictions.) Each area was meant to protect Iraqi populations persecuted by Saddam Hussein leading up to the war: Operation Northern Watch was meant to shield Iraqi Kurds, while Operation Southern Watch was supposed to defend Shiite Muslims. Each no-fly zone remained officially in place until Hussein was removed from power in 2003.

Bosnia: At the onset of the Bosnian War in October 1992, the UN Security Council passed a resolution to prohibit unauthorized military aircraft in Bosnian airspace. NATO launched Operation Sky Monitor to keep track of any violations, without engaging any aircraft in battle. After documenting over 500 such violations, NATO pushed the UN for further action and in April 1993, a new resolution allowed NATO to enforce the ban. On Apr. 12, NATO forces began Operation Deny Flight, with hopes that more aggressive action would facilitate a quicker end to the bloody conflict.

Were they successful?

As with any military action, success is a relative term. In Iraq, it is important to note that both no-fly zones were not established in conjunction with a specific Security Council resolution. In 1998, Saddam Hussein put a bounty on any Allied planes shot down by Iraqi forces, although no such incidents ever occurred. France withdrew its support for the no-fly zone the same year, citing the ineffectiveness of the no-fly zones in ending tensions on the ground. Critics said the continued Allied involvement by the U.S. and Britain was in breach of international law.

The consensus on the impact of the no-fly zone in Bosnia is that while it succeeded in helping neutralize Serbian air attacks, the war only truly shifted when Operation Deny Flight transitioned into Operation Deliberate Force — namely, the large-scale bombing of key Serbian targets. The most significant takeaway from the implementation of a no-fly zone over Bosnia was that it showed NATO’s willingness to work with the UN to engineer a peaceful end to a horrific war.