Gun Image Gallery
Gun Image Gallery

A Libyan man fires his pistol in the air during a celebratory rally, after the United Nations approved a no-fly zone over the country on March 18, 2011. See more gun pictures.

Joe Raedle/Getty Images

After the airplane was invented, it only took a few decades for the world's despots to realize how air power could be used to wipe out rebels and/or terrorize civilian populations. The most chilling early example was the Spanish fascists' 1937 attack on the town of Guernica, the cultural capital of the democracy-supporting Basques. In a three-hour-long onslaught, bombers and fighter aircraft dumped 100,000 pounds of high explosives and incendiary bombs on the town, reducing it to rubble, and strafed inhabitants as they tried to escape. Some 1,600 people were killed or wounded. The world responded with horror and outrage, but the international organizations of the time were too weak and unprepared to stop further bloodshed [source: PBS].

Today, however, the United Nations and the North Atlantic Treaty Organization (NATO) have a tool to prevent such aerial atrocities. Starting in the early 1990s, international military coalitions began imposing no-fly zones. A no-fly zone is an area within a nation in the midst of a civil war or rebellion, in which an oppressive regime's air forces are banned, preventing that regime from attacking rebel forces and civilians.

No-fly zones, which have been declared in Iraq and the Balkans in the 1990s and most recently in Libya, have always been controversial. They require an international organization to enter a sovereign nation, overrule the authority of a legally recognized government, and, at least to a degree, to take sides in an internal conflict. To make a no-fly zone effective, the interveners have to be willing and prepared to confront a rogue regime's aircraft if they violate the ban, and to either engage them in aerial combat or shoot them down with land- or ship-based antiaircraft missiles. That entails the risk that coalition planes may be shot down, and their crews captured or killed. To protect themselves and make the ban more effective, interveners usually must also attack and destroy a regime's airfields, radar installations and anti-aircraft weaponry. That level of force can make a humanitarian intervention start to look more and more like the opening salvo in a strange, problematic sort of war -- one in which one side is constrained by the limits of its mandate from achieving victory.

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.