Libya's current politics offer two lessons -- ones we really shouldn't have to learn yet again. First, military interventions that topple repressive regimes invariably offer occasions to observe, though at others' expense, the law of unintended consequences. Second, the constituencies that clamor for such campaigns move quickly to other matters once those malign consequences become manifest.

The defenders of the Libyan intervention claim that the March 17 UN Security Council resolution authorized a no-flight zone in the face of imminent mass atrocities. But by now, no one seriously disputes that the assignment soon metamorphosed, allowing NATO and a few Persian Gulf states to take sides in a civil conflict, and in ways -- targeting Mu'ammar Gaddafi's forces, equipping and training the armed resistance, and even dispatching special forces -- that proved decisive.