CONTRAST THE clarity of the U.S. strike on Osama bin Laden with an event about 24 hours earlier: Several missiles or guided bombs hit a Tripoli villa, killing — according to the regime — one of Moammar Gaddafi’s sons and three of his grandchildren and narrowly missing the dictator and his wife. The bin Laden strike was proudly announced by President Obama, but the NATO alliance refused to say which country’s forces attacked the Gaddafi home. Killing or capturing al-Qaeda’s leader had been declared U.S. policy for a decade. But the United States and its allies deny they are trying to kill Mr. Gaddafi.

For the record, we think targeting Mr. Gaddafi and his sons — if that is what is really going on — is as legitimate as striking al-Qaeda. The Libyan leader presides over military units that are intentionally targeting civilians, using weapons ranging from sniper rifles to artillery and rockets. Thousands of civilians have been killed, and more are dying every day.

In the beseiged port city of Misurata, relief ships have been unable even to evacuate the wounded, much less the more than 1,000 foreign migrants, including women and children, camped in the port. The prosecutor of the International Criminal Court said Tuesday that there are “reasonable grounds” to charge the regime with war crimes and crimes against humanity.

Moreover, targeting Mr. Gaddafi may be the quickest way — and maybe the only way— to stop his carnage. The dictator has refused to step down or call off his forces, many of which are foreign mercenaries led by his sons. Though an opposition government has been coalescing in the eastern city of Benghazi, its military forces appear to be nowhere near ready to capture the Gaddafi-controlled West. That leaves NATO stuck in a military intervention of indefinite duration while the civilians it wants to protect continue to die.

It’s not very surprising, then, that twice in less than a week, NATO airstrikes demolished buildings associated with Mr. Gaddafi. On April 25, two missiles struck the complex where he lives, destroying offices and a library. Not just the dictator’s spokesmen but Russian officials are calling these assassination attempts. Yet U.S. and NATO spokesmen insist the strikes are merely aimed at “command and control” structures. The Canadian commander of the operation insisted in one briefing that the bombing was “not about individuals” and “not about regime change.”

Such dubious assertions are the logical product of an operation being conducted by an unwieldy coalition under U.N. auspices. Apart from the muddled message they send to Libyans and the world, they reflect the deeper mismatch between NATO’s actual aim — to overturn the Gaddafi regime — and the means so far devoted to it. Sen. John McCain (R-Ariz.) may have done the Obama administration a favor last Sunday when he spelled out a mission that actually makes sense. “We should be taking out his command and control,” Mr. McCain said on CBS’s “Face the Nation.” “And if he is killed or injured because of that, that’s fine.”