Fareed Zakaria, as usual, is very smart:
Over the past five decades, the U.S. has had very mixed results when it has intervened, by air or land, in other people's wars. But it has done pretty well when it has helped one side of the struggle. Arming rebels in Afghanistan, Central America and Africa has proved to be a relatively low-cost policy with high rates of success. Giving arms, food, logistical help, intelligence and other such tools to the Libyan opposition would boost its strength and give it staying power.
Once Gaddafi realizes that he is up against an endless supply of arms and ammunition, he will surely recalibrate his decisions. There have been reports that he floated the idea of leaving office as long as he is guaranteed safe passage. At a weak moment, he made a plea that he be treated like Britain's Queen or the King of Thailand, a figurehead with no powers.
Some worry that if we arm the rebels, things might turn out the way they did in Afghanistan, where the freedom fighters became Islamic jihadists and turned their sights on us. But that's not really what happened. After the Soviet defeat, the U.S. abandoned Afghanistan, leaving it open to Islamic jihadists backed by the Pakistani military. The better analogy is to Chechnya, where as the civil war continued, the rebels became more radical and Islamic fundamentalists jumped into the fight and soon became its leaders. The best way to prevent al-Qaeda from turning Libya into an area of strength would be to have the fighting end — with Gaddafi's defeat. So let's help the Libyan opposition do it.