President Barack Obama said the U.S. and its allies had to take military action in Libya to avert a massacre of civilians that would have “stained the conscience of the world.”

In an address to the nation last night, Obama offered a rationale for committing U.S. armed forces in the North African country based on humanitarian ideals and national interests that set clear contrasts to the way his two immediate predecessors responded to foreign crises.

“Some nations may be able to turn a blind eye to atrocities in other countries,” Obama said at the National Defense University in Washington. “The United States of America is different.”

Obama’s speech, coming nine days after the U.S. airstrikes against Libya began, was his first televised address directly to the American people justifying his use of force. Leading Republicans and some members of his own party have criticized the president for not explaining the mission’s objectives.

He stuck with his insistence that Muammar Qaddafi must relinquish power, while declaring that expanding the allied military mission to overthrow the Libyan regime would be a “mistake.”

The president also touched on the broader turmoil sweeping across the Middle East and North Africa, saying the instability in Libya could threaten the fragile democratic transitions in Egypt and Tunisia. He said the U.S. role in Libya would be limited, without giving a timeline for the military campaign.

The upheavals in the region have raised concern that crude supplies from the Middle East could be reduced. Oil prices have jumped more than 20 percent since the mid-February outbreak of the rebellion in Libya, which holds Africa’s largest proven reserves.

He used the speech to mark the progress that the alliance has made in stopping the advance of Qaddafi’s forces and announced that the North Atlantic Treaty Organization would assume command of the entire operation tomorrow.

While insisting that Libya presented a unique circumstance, he argued that the U.S. was compelled to respond to crises that “threaten our common humanity” as long as the country can assemble an international coalitions to share the burden.

And without mentioning former Presidents Bill Clinton or George W. Bush by name, Obama, 49, suggested he is choosing a different approach than they did in using the military as a policy instrument.

He said he “refused to wait for the images of slaughter and mass graves before taking action,” a charge that has been leveled against Clinton’s responses in Bosnia and Rwanda.

In arguing against using the military to overthrow Qaddafi, Obama said it would splinter the coalition and probably require troops on the ground.

“To be blunt, we went down that road in Iraq,” said Obama, who ran as a candidate for president as an early critic of Bush’s decision to go to war in 2003. “Regime change there took eight years, thousands of American and Iraqi lives, and nearly a trillion dollars. That is not something we can afford to repeat in Libya.”

Obama has drawn objections from leading Republicans and some Democrats that he hasn’t explained the mission’s objectives or the full scope of the nation’s commitment. On the eve of the speech, much of the public perceived a murky military commitment.

(Source: Bloomberg)