Obama: NATO to command Libya operation

Defending the first war launched on his watch, President Barack Obama declared Monday night that the United States intervened in Libya to prevent a slaughter of civilians that would have stained the world's conscience and "been a betrayal of who we are."

Yet he ruled out targeting Moammar Gadhafi, warning that trying to oust the Libyan leader militarily would be a costly mistake.

Obama announced that NATO would take command over the entire Libya operation Wednesday, keeping his pledge to get the United States out of the lead -- but offering no estimate on when the conflict might end.

He never described the U.S.- led military campaign as a "war" and gave no details on its costs, but he offered an expansive case for why he believed it was in the national interest of the United States and its allies to act.

In blunt terms, Obama said the U.S.-led response had stopped Gadhafi's advances and halted a slaughter he warned could have shaken the stability of an entire region.

"To brush aside America's responsibility as a leader and -- more profoundly -- our responsibilities to our fellow human beings under such circumstances would have been a betrayal of who we are," he said.

Obama spoke to a respectful military audience at the National Defense University. The address to the nation was the president's most aggressive attempt to answer the questions mounting from Republican critics, his own party and war-weary Americans -- chiefly, why the United States was immersed in war in another Muslim nation at a time when the nation is all but buried in debt.

Obama sought to counter criticism from both left and right. Some Democrats are disappointed that Obama, a Nobel Peace Prize laureate, would initiate military action against a third Muslim country after inheriting wars in Iraq and Afghanistan.

Some Republicans say Obama waited too long to help anti-Gadhafi forces, while others argue the United States should not intervene in a conflict that does not directly affect its national security.

Sen. John McCain (R-Ariz.), the top Republican on the Senate Armed Services Committee, reacted with a mix of praise and criticism. "I welcome the president's clarity that the U.S. goal is for Gadhafi to leave power," he said in a statement. "But an equal amount of clarity is still required on how we will accomplish that goal."

Amid protests and crackdowns across the Middle East and North Africa, Obama stated his case that Libya stands alone. "In this particular country, at this particular moment, we were faced with the prospect of violence on a horrific scale," he said.

Obama took pains to say why he chose to intervene in Libya even while acknowledging that America's military cannot be used to stamp out every instance of repression.

"There will be times when our safety is not directly threatened, but our interests and values are," he said. "Sometimes, the course of history poses challenges that threaten our common humanity and common security . . . These may not be America's problems alone, but they are important to us, and they are problems worth solving."

The president also reiterated the White House position that Gadhafi should not remain in power but the United Nations resolution does not go that far.