As President Obama prepared to address the nation Monday night about US operations in Libya, some defense analysts are arguing that there remains a fundamental tension in America’s goals on the ground.

President Obama has said that it is time for Libyan leader Muammar Qaddafi "to step down from power and leave.” Yet administration officials have also said that they can envision a scenario in which operations end, and yet Mr. Qaddafi remains in power. This raises the question of whether an operation that does not result in Mr. Qaddafi’s ouster could be considered a success, expert say.

“I cannot conceive of any operation or campaign that doesn’t achieve that goal being a success,” says Tom Donnelley, director of the Center for Defense Studies at the American Enterprise Institute.

The tension facing Mr. Obama is being called the “Goldilocks” dilemma: He wants to find the right mix of economic and diplomatic pressure to oust Qaddafi without targeting him militarily. But experts ask if it is strategically viable to aspire to push Qaddafi out, but to be unwilling to use the US military to do it.

On the one hand, President Obama has made it clear that he wants Qaddafi gone, says Michael O’Hanlon, senior fellow at the Brookings Institution. On the other hand, however, the United Nations Security Council resolution makes it clear that Qaddafi’s overthrow is “not the explicit goal.”

US military commanders, for their part, do not view the ouster of Qaddafi as their mandate. “I have a very discrete military mission. And so I could see accomplishing the military mission, and the current leader would remain the current leader," Gen. Carter Ham, the head of US Africa Command, said last week. "Is that ideal? I don’t think anyone would say that is ideal, but I could envision that as a … possible situation, at least for the current mission that I have.”

Obama has assured Americans that he will not commit ground troops to the war in Libya. It is possible that the rebels, who have benefited from NATO air power to make some inroads toward the center of Libya, will ultimately emerge successful.

“Maybe they’ll just keep on going and be done in a few weeks,” says Dr. O’Hanlon, echoing a widespread hope within the administration and among NATO allies.

Yet there is also the possibility of a stalemate. In this event, in the weeks to come the administration is going to have to figure out if they are going to escalate US military operations in Libya.

This might involve arms transfers to the opposition or even Special Operations forces. “The use of air power plus Special Forces on the ground did remarkable things in conjunction with the Northern Alliance” in Afghanistan, O’Hanlon points out, referring to the overthrow of the Taliban in 2001.

Yet the Libyan rebel forces do not have the skills or the long-time fighting experience of the Northern Alliance. But the Libyan military isn’t the Taliban, either, says Kenneth Pollack, director of the Saban Center for Middle East Policy at Brookings and a former CIA analyst.

And it still may be possible to build up Libyan opposition forces without NATO ground forces that could inflame tensions with the Arab League. “That,” says Dr. Pollack, “is what we’ve got a CIA for.”