Repetition does not make it any less true: We know how to start wars, but we do not know how to end them.

The political and military crisis in Libya differs from the crises of its neighbors, Egypt and Tunisia. In those countries, the struggle for better living conditions and democratic freedom encompassed vast sectors of society. Their rulers were deposed by waves of mass protests.

In the case of Libya, fatigue is also a factor after more than four decades of dictatorship by Moammar Gadhafi. However, unlike its neighbors, there is a regional and tribal component that engenders fear of a protracted conflict, or even a civil war, in which neither side can prevail, at least in the short term.

The United States and Great Britain have taken the lead in raising the possibility of military intervention by arguing that there is a humanitarian imperative to protect those who have risen against the Libyan regime. The West recognizes the great political risk in sending troops, but at the same time, it is confident of its military supremacy in the air. Therefore, it is discussing the idea of imposing a “no-fly zone” aimed at blocking action by the Libyan air force.

The risks of such an operation are high. It will require more than shooting down planes that threaten the opposition. More than likely, it will require silencing the batteries of anti-aircraft missiles Libya possesses.

The political impact of Western warplanes over Libya and possible attacks could be enormous. In the first place, it could provoke an outburst of nationalist sentiment favoring the regime. It could also undermine the legitimacy of the opposition, which already controls much of the territory.

The bitter memories of colonial times would be painful. Even worse, the Libyan population — like the rest of the Arab world — has seen the futility and disastrous impact of intervention in Iraq by Washington and London. If the rebels are associated with foreign powers, charges of imperialism made by Gadhafi will gain credibility.

The world has seen large-scale massacres, like those that took place in Rwanda, the Democratic Republic of Congo and other African countries. They took place in full view of a passive international community, which did not feel compelled to intervene to save hundreds of thousands of innocent lives.

Libya, by contrast, is a major exporter of oil and gas.