The actual context, as usual, puts a more reaosnable light on what Obama actually says, as opposed to what his detractors like to pretend he is saying.

"Yet for Obama, who opposed the Iraq invasion, the episode offered an opportunity for him to present his approach as entirely different from those of his colleagues. In a letter to supporters titled "The war we need to win," he called for the country to "stop fighting the wrong war" and to focus on the al-Qaeda threat, which he said became a lower priority after the Iraq war began.

U.S. officials rarely rule out nuclear attacks as a matter of diplomacy, preferring to keep the threat as a deterrent. Yet several foreign policy experts said Obama was essentially right: It would be unwise to target an individual or a small group with nuclear weapons that could kill civilians and worsen the United States' image around the world.

Michael O'Hanlon, a Brookings Institution scholar, said Obama "clearly gave the right answer."

"He's certainly right to say you would never use a nuclear weapon to get Osama bin Laden," he said. He said that if intelligence officials were able to locate bin Laden with the precision required for a nuclear attack, they would also be able to catch or kill him by more conventional means that would not signal to the world that using nuclear force is acceptable.

The Obama campaign was still responding to the uproar late in the afternoon. "If we had actionable intelligence about the existence of high-level al-Qaeda targets like Osama bin Laden, Senator Obama would act and is confident that conventional means would be sufficient to take the target down," said Bill Burton, a campaign spokesman. "Frankly we're surprised that others would disagree.""

(Same article, different paragraph, as cited above from WaPo)