By Susan Cornwell
WASHINGTON (Reuters) - The State Department's top lawyer on Tuesday defended the legality of the U.S. military involvement in Libya as some lawmakers accuse President Barack Obama of violating a 1973 law requiring congressional authorization.
State Department legal adviser Harold Koh urged U.S. lawmakers to nonetheless vote for a resolution authorizing the U.S. role in the NATO-led mission. He said this would show a "united front" with U.S. allies and help to ensure that Libyan leader Muammar Gaddafi does not get the upper hand in his country's civil war.
There is a simmering controversy in Washington over whether Obama has violated the War Powers Resolution, passed during the Vietnam War era.
The law sets out the powers of the president and Congress regarding U.S. military actions and prohibits U.S. armed forces from being involved in military actions for more than 60 days without congressional authorization.
The New York Times has reported that Obama ignored the advice of Pentagon and Justice Department lawyers who argued that the U.S. bombing runs over Libya, under NATO command, met the definition of "hostilities" set out in the 1973 law and necessitated congressional authorization.
The Times reported that Obama instead latched onto legal advice from inside the White House and the State Department that the bombing missions fell short of "hostilities" and that they could continue without the green light from Congress.
"It is regrettable that the administration has refused our requests to make witnesses from the Departments of Defense and Justice available for today's hearing," said Senator Richard Lugar, the Senate Foreign Relations Committee's senior Republican.
Koh told the committee in prepared testimony that he believed Obama was acting lawfully in Libya, and that Obama had consulted "extensively" with Congress on the action, an assertion many U.S. lawmakers dispute.
"The President has never claimed the authority to take the nation to war without congressional authorization, to violate the War Powers Resolution or any other statute," Koh said.
"We recognize that our approach has been a matter of important public debate, and that reasonable minds can disagree. But surely none of us believes that the best result is for Gaddafi to wait NATO out, leaving the Libyan people again exposed to his brutality," Koh said.
The House of Representatives, in a rebuff to Obama, last week refused to formally authorize the Libya mission.
The committee was expected to vote later on Tuesday on a resolution sponsored by Senators John Kerry, a Democrat, and John McCain, a Republican, that would authorize the U.S. role in Libya.
Koh's arguments were not expected to win over everyone on the Senate panel.
"Even if one believes that the president somehow had the legal authority to initiate and continue U.S. military operations in Libya, it does not mean that going to war without Congress was either wise or helpful to the operation," Lugar said.
The U.S. intervention was not extensive enough in "nature, scope and duration" to require a congressional declaration of war under Article One of the U.S. Constitution, Koh said.
Nor did it constitute the kind of hostilities envisioned by the War Powers Resolution, he said. That measure, passed by Congress over then-President Richard Nixon's veto years into the undeclared Vietnam war.
This was because there were limits to the mission as well as the exposure of U.S. armed forces, Koh said. The risk of escalation and the military means used by the United States were also limited, he said. The violence that U.S. armed forces have directly inflicted or facilitated after the handoff to NATO has been "modest", he said.
(Editing by Warren Strobel and Will Dunham)