"History has demonstrated that an entrenched enemy, like the Libyan regime [of Moammar Gadhafi], can be resilient to air power," said Rep. Howard McKeon, R-Calif., chairman of the House Armed Services Committee, said in his opening remarks. "If Gadhafi does not face an imminent military defeat or refuses to abdicate, it seems that NATO could be expected to support a decade-long no-fly zone enforcement, like the one over Iraq in the '90s."
Defense Secretary Robert Gates and Joint Chiefs of Staff Chairman Adm. Michael Mullen were the only witnesses at the hearing on U.S. military operations in Libya.
McKeon said it wasn't his intent to "second-guess or undermine the administration's authority. But I would like an explanation of the nature of this threat, and how American interests will be advanced through the use of military power."
Democrats, too, have asked why the U.S. involvement in the country, Rep. Adam Smith, D-Wash., the top Democrat on the panel.
"Many have asked the question, you know, why Libya, but not some of the other places that have civil wars or disruptions going on?" Smith said in his opening statement.
Smith said he believed "there were a unique set of circumstances in Libya that warranted this action."
But it was important to explain what the circumstances were and "let the American people know that this is not something we're going to be doing in a great number of places," he said.
Gates, in his opening statement, said the NATO-led mission is a limited one, just as the coalition's mission before. NATO's mission, which began Thursday, is to maintain pressure on Gadhafi's remaining forces to prevent attacks on civilians, enforce the no-fly zone and arms embargo, and provide humanitarian relief.
"There will be no American boots on the ground in Libya," Gates told the committee, saying U.S. involvement would be limited to operations such as electronic attack, aerial refueling, search and rescue, intelligence, surveillance and reconnaissance support.
Deposing the Gadhafi regime, "as welcome as that eventuality would be," isn't part of the military mission, the Pentagon chief said.
Mullen said no one is underestimating the challenge in Libya.
"Gadhafi still possesses superior military capability to those of the forces arrayed against him. He still shows every desire of retaking lost ground and, in fact, did so yesterday [Wednesday]," Mullen said. "He still denies his own people food, water, electricity and shelter. ... And he has made no secret of the fact that he will kill as many of them as he must to crush the rebellion."
During questioning, Gates said he couldn't offer a timetable for Gadhafi's removal, which Obama has stated as a U.S. goal and appears to be a "mismatch" of the military mission of protecting Libyan civilians, McKeon said.
"I think the one thing that may make a difference in terms of how long it takes for this regime to change is the fact that we continue to degrade his military capabilities, and I think that may contribute to some cracking of the unity of his own military," Gates said. "The bottom line is, no one can predict for you how long it will take for that to happen."
Smith asked Gates about Obama's bypassing Congress when the coalition airstrikes began.
"I think there's considerable consternation about that, particularly amongst my fellow members of Congress," Smith said.
Gates said -- and Smith agreed -- that Congress was consulted the day before the airstrikes began March 19.
"[The] president actually did not make his final decision on what to do until Thursday night" then consulted with congressional leaders the next day, Gates said.
"Even before the White House knows exactly what it's going to do, there is some benefit to bringing leadership in Congress into the discussion in terms of building support here," Smith said. "And I think that would have helped build more support in Congress if we felt we knew the thinking process leading up to that decision."
Ahead of the congressional hearing, U.S. officials said President Obama secretly authorized the CIA to provide arms to Libyan rebels. Weapons have not yet been shipped to the rebels, the officials said, because administration officials still debated the consequences of giving advanced weapons to little-known fighters, including some alleged to have ties to militant Islamist groups al-Qaida and Hezbollah.
Obama's order, known as a presidential finding, authorized the CIA to put operatives on the ground in Libya to support the rebels seeking to overthrow leader Moammar Gadhafi, the officials told several news organizations.
Operatives of the CIA and other Western intelligence services have been on the ground in Libya for weeks, officials said.