Gadhafi's mercenaries and militia were slaughtering outgunned civilian rebels when the U.N. Security Council authorized a "no-fly zone" over Libya. The United States, Britain, France and others used the authorization largely to destroy Gadhafi's antiaircraft defenses and some of his forces on the ground, giving the rebels breathing room.
But the question for many in Congress is whether President Barack Obama had the authority to order such military action.
Article 1 of the Constitution gives Congress the sole power to declare war. However, the last time Congress declared war was after the 1941 attack on Pearl Harbor.
Since then presidents have used the military as a regular extension of U.S. foreign policy, so much so that Congress enacted the War Powers Resolution, commonly referred to as the War Powers Act, in 1973. President Richard Nixon's veto of the resolution was massively overridden: 284–135 in the House, and 75–18 in the Senate, more than the two-thirds needed, and the resolution became law.
The War Powers Resolution says the president, as commander in chief, can put U.S. forces in harm's way only after a declaration of war, specific statutory authorization or a national emergency created by an attack on the United States or its military.
The resolution also requires the president "in every possible instance to consult with Congress before introducing U.S. forces into hostilities or imminent hostilities unless there has been a declaration of war or other specific congressional authorization," the Congressional Research Service says. "It also requires the president to report to Congress any introduction of forces into hostilities or imminent hostilities ... or in numbers which substantially enlarge U.S. forces equipped for combat already in a foreign nation."
The law says once the president submits a report, "Congress must authorize the use of forces within 60 to 90 days or the forces must be withdrawn."
To say that presidents have viewed the War Powers Resolution with a jaundiced eye is an understatement.
Every president since 1973 has taken the position that the resolution is an unconstitutional infringement on presidential authority, the CRS says -- though the U.S. Supreme Court and the other federal courts have never directly ruled on the issue. The one foray into legally trying to hold a president accountable to the War Powers Resolution did not turn out well for members of Congress.
Obama's use of force in Libya has raised congressional hackles. Predictably, U.S. Rep. Dennis Kucinich, D-Ohio, brought up impeachment in an interview with The Raw Story weblog, as reported by clevelandleader.com.
Kucinich said the fact Obama acted on his own without congressional approval "would appear on its face to be an impeachable offense," though he doubted Congress had the nerve to follow through.
Other congressional criticism was more muted. U.S. House Speaker John Boehner, R-Ohio, supported the no-fly zone, but said, "Before any further military commitments are made, the administration must do a better job of communicating to the American people and to Congress about our mission," The Huffington Post reported.
Rep. Buck McKeon, R-Calif., the chairman of the House Armed Services Committee, also called for Obama to explain the Libyan operation to the U.S. public.
The Huffington Post interviewed other members of Congress with sharper views who questioned whether there was a threat to the United States as required by the War Powers Resolution.
Rep. Jason Chaffetz, R-Utah, said: "I think (Obama) has a duty and an obligation to come to Congress. I see no clear and present danger to the United States of America. I just don't. We're in a bit of the fog at the moment as to what the president is trying to ultimately do."
"In the absence of a credible, direct threat to the United States and its allies or to our valuable national interests, what excuse is there for not seeking congressional approval of military action?" liberal Rep. Jerry Nadler, D-N.Y., asked. "I think it is wrong and a usurpation of power and the fact that prior presidents have done it is not an excuse."
Another liberal, Rep. Anthony Weiner, D-N.Y., was supportive but cautious, CBS News reported.
"I think it is important that we show that we're a powerful country who is willing to step in and protect those who are not able to protect themselves," he said. "I do believe though that the president should have and should still come to Congress for authorization."
Obama has in fact "consulted" with Congress in a way, calling in representatives of congressional leaders to the White House before his South American trip, not to ask for permission but to explain to them what he was doing.
And last week, while the president was abroad, the White House released a letter from the president to Boehner and the president pro tempore of the U.S. Senate, Sen. Daniel Inouye, D-Hawaii. In the letter, dated March 21, Obama said he was informing Congress of the Libyan operation "consistent with the War Powers Resolution."
Obama told the congressional leaders "at my direction, U.S. military forces commenced operations (on March 19) to assist an international effort authorized by the United Nations Security Council and undertaken with the support of European allies and Arab partners, to prevent a humanitarian catastrophe ... "
The president added: "U.S. military forces, under ... U.S. Africa Command, began a series of strikes against air defense systems and military airfields for the purposes of preparing a no-fly zone. These strikes will be limited in their nature, duration, and scope. ... These limited U.S. actions will set the stage for further action by other coalition partners."
The resolution authorizes U.N. member states "to take all necessary measures to protect civilians and civilian populated areas under threat of attack in Libya, including the establishment and enforcement of a 'no-fly zone' in the airspace of Libya. United States military efforts are discrete and focused on employing unique U.S. military capabilities to set the conditions for our European allies and Arab partners to carry out the measures authorized by the U.N. Security Council Resolution."
Obama said Gadhafi was sent "a very clear message that a cease-fire must be implemented immediately," but though Libya's foreign ministry announced an immediate cease-fire Gadhafi's forces continued to advance.
"Left unaddressed, the growing instability in Libya could ignite wider instability in the Middle East, with dangerous consequences to the national security interests of the United States," Obama contended.
"The United States has not deployed ground forces into Libya," the president said. "United States forces are conducting a limited and well-defined mission in support of international efforts to protect civilians and prevent a humanitarian disaster."
Obama said he ordered the Libyan actions, "which are in the national security and foreign policy interests of the United States, pursuant to my constitutional authority to conduct U.S. foreign relations and as commander in chief and chief executive.
"I am providing this report as part of my efforts to keep the Congress fully informed, consistent with the War Powers Resolution. I appreciate the support of the Congress in this action."
Significantly, Obama used the phrase "consistent" with the resolution, as have presidents before him, rather than "pursuant" to the resolution, which would indicate the resolution was accepted law that had to be obeyed.
Presidential use of military force without specifically meeting the provisions of the War Powers Resolution was challenged in court in March 1999 by 18 Republican members of Congress led by Rep. Tom Campbell of Texas.
President Bill Clinton had ordered U.S. forces to participate in the NATO bombing operation over Kosovo to stop the "ethnic cleansing" and massacres of ethnic Albanian Muslims.
A series of House and Senate votes supporting or opposing the war left the issue up in the air though Congress eventually passed emergency funding that underwrote the operation.
On April 30, 1999, Campbell and 17 other House members filed suit in federal court asking for a ruling that would require the president to get authorization from Congress for the Kosovo bombings or discontinue military operations.
On May 25, 1999, the 60th day of military operations passed. The congressional group at that time told the federal court that Clinton was in violation of the War Powers Resolution, which required hostilities to cease after 60 days in the absence of congressional approval or a presidential request for an extra 30 days to safely withdraw from combat.
However, Clinton did not ask for the extension, instead maintaining the War Powers Resolution was constitutionally defective.
All the congressional and presidential Sturm und Drang turned out to be moot. U.S. District Court Judge Paul Friedman dismissed the suit, saying Campbell and the others had no standing to bring it in the first place. The U.S. Court of Appeals for the District of Columbia Circuit, sometimes called the second-most powerful court in the country, agreed.
The appeals court panel said the U.S. Supreme Court -- as recently as 1997 -- had refused to recognize the right of members of Congress to sue the executive branch. Besides, the panel's prevailing opinion said, the case essentially presented a political, not a legal, controversy.
Citing its own precedent, the appeals court said: "It is uncontested that the Congress could terminate the (contested program) were a sufficient number in (the U.S. House and Senate) so inclined. Because the parties' dispute is therefore fully susceptible to political resolution, we would (under circuit precedent) dismiss the complaint to avoid 'meddling' in the internal affairs of the legislative branch."
The congressional group then asked the U.S. Supreme Court for review. The high court declined without comment.