The United States participated in military strikes against Libya this weekend where Colonel Muammar Gaddafi remained in power despite a mass uprising in the east of his country. To prevent the regime from massacring its own people, the United Nations authorized an intervention on Thursday. Britain, Canada, France, Italy, Spain and the United States had been involving in patrolling the skies of Libya as of this weekend and launched air and missile strikes against Libyan armor and anti-aircraft defenses.

According to the chairman of the American Joint Chiefs of Staff, Admiral Michael Mullen, the allied action had already had a “very significant impact” as of Sunday “in establishing this no-fly zone.”

Nineteen American warplanes, including Marine Corps Harrier jets, Air Force B-2 stealth bombers and F-15 and F-16 fighter jets, conducted strikes in the morning. The previous night, American and British guided-missile destroyers and submarines off the Libyan coast had deployed cruise missiles against some twenty air defense facilities ashore.

“The no-fly zone is effectively in place,” Mullen said on CNN’s State of the Union. “We’ve got combat aircraft over Benghazi and we’ll have them there on a 24/7 basis, start to move that to the west.” Most air defenses and several airfields had been disabled. “Now we’ll look to cut off his logistics.”

Although French aircraft were the first to target Libyan tanks near the city of Benghazi in the east of Libya on Saturday, the United States were taking the lead in terms of the coalition, according to Admiral Mullen. “General Carter Ham, American commander of USAFRICOM, is actually the commander right now,” he said on ABC’s This Week.

In the coming days or weeks, the United States would move into a supportive role in enforcing the no-fly zone, providing intelligence and jamming Libyan communications, “but I haven’t been given a date by the president where American military participation here would end,” Mullen said on Fox News Sunday.

Democrat Carl Levin, who chairs the Senate Armed Services Committee, was unambiguous about the administration’s intentions however. He told NBC’s Meet the Press that within days, there would be a “hand off” to America’s allies “and this mission will then by carried on by French, by British and by Arab countries.”

While Admiral Mullen emphasized the limited and “clearly defined” nature of the operation, Senator Richard Lugar, the top Republican on the Foreign Relations Committee, argued that the operation lacked sufficient clarity and that Congress should be consulted “if we’re going to war with Libya.”

The Indiana Republican worried that the coalition wasn’t sure whom it was trying to support. “Obviously the people that are against Gaddafi,” he said on CBS’ Face the Nation, “but who?”

“We had better get this straight from the beginning,” Lugar added. “Or there is going to be a situation in which war lingers on — country after country, situation after situation — all of them on a humane basis, saving people.”

Senator Jeff Sessions of Alabama was also concerned about the lack of a clearly defined objective. He warned on Meet the Press that the West “could end up with the rebels having lost momentum and creating a prolonged stalemate.”

Although both Admiral Mullen and the administration had stressed that regime change wasn’t part of the Western intervention, another senior Republican, Lindsey Graham of South Carolina, said on Fox News Sunday that its goal should be to “isolate, strangle and replace” Gaddafi. Others legislators disputed this, noting that the operation was sanctioned by the United Nations to protect civilians.