These strikes are not based on doubtful evidence. Qaddafi has said plainly what he intends to do to civilians who resist, even peacefully, and he has demonstrated repeatedly that he is prepared to carry out his threats. Even on the morning of the attacks, his armor entered Benghazi, in clear contradiction of his own Foreign Minister's declaration that Tripoli would respect the cease-fire. Later Qaddafi's spokesman disowned the foreign minister's statement.

There is a solid coalition backing the military action, one that includes several Arab countries as well as the U.S., France and the United Kingdom. Even the Italians, who have historically close relations with Libya and even with Qaddafi personally, are on board. Iraq, Qatar, Jordan, Morocco, and the United Arab Emirates were present for the meeting in Paris that launched implementation of the UN resolution, as was the Arab League. (Saudi Arabia was missing.) While Russia, China, India, and Brazil were absent, Germany was present.

The U.S., while it has claimed outsized credit for the diplomacy, is not visibly in the lead of the military action. UK and France have claimed that honor, with NATO as the operational forum. American contributions are likely to be substantial, in particular when it comes to cruise missiles, intelligence, command-and-control, and other U.S. assets. But this is not an American operation with a coalition tacked on.

Which leaves the question of purpose. Is this offensive, like the U.S.-led invasion of Iraq, an effort at regime change, with Qaddafi the ultimate target? Or is the objective, as Hillary Clinton claimed after the Paris meeting, only to protect civilians? For the moment, this is a distinction without a difference. Unless Qaddafi changes not just his tune but his behavior, he represents an imminent threat to civilians throughout Libya. It is up to him to convince the coalition that he is prepared to change his behavior, as he successfully did in 2003 when he gave up his nuclear weapons program.

But it seems Qaddafi won't change: He appears as attached to the use of force against his people as Ratko Mladic was against thousands of Muslims in Srebrenica, Bosnia. Qaddafi rightly knows he can only stay in power if he can kill Libyans.

Srebrenica, not Iraq, is the right historical precedent for what is happening in Libya. In 1995 the West failed its declared intention to protect civilians in a Muslim-populated enclave in eastern Bosnia, declared a "safe area" by the UN. There weren't enough Dutch peacekeepers in the area to defend the Muslims and, as a result, thousands of men and boys were massacred in cold blood.

Only a few weeks later NATO responded to Serb attack on another "safe area," Sarajevo. NATO launched a bombing campaign that broke apart the Bosnian Serb Army and allowed Croat and Muslim Federation forces to advance on the Serb army. As the Serbs reeled from the air attack, they took hostages and used them as human shields. They also parked armored vehicles near mosques and schools. We should expect Qaddafi to do likewise.