Islamic State fighters take part in a military parade along the streets of northern Raqqa province, June 30.Stringer/Reuters
President Barack Obama wants Congress to clearly legitimize the bombing war he launched six months ago in Iraq and Syria against Islamic State.
It will be the first such "war vote" Congress has taken in 13 years, since it approved George W. Bush's invasion of Iraq.
Mr. Obama initially claimed he didn't need any new authority to wage war against the so-called Islamic State, arguing that the 2001 "authorization of the use of military force" or AUMF – passed overwhelmingly by both houses of Congress three days after al-Qaeda hijackers using civilian airliners as human-guided missiles destroyed New York's twin towers and set the Pentagon ablaze – was good enough to cover the attacks on the jihadi extremist group.
But as the attacks have ramped up, and with U.S. warplanes flying 1,800 bombing sorties since Mr. Obama ordered the air strikes last August, the President announced in November that he would seek a new force authorization. More than 450 air strikes have been flown by warplanes from other nations, including Canada, in the U.S.-led coalition which has no authorization from the United Nations Security Council.
"The President believes it sends a very powerful signal to the American people, to our allies, and even to our enemies, that the United States of America is united behind this strategy to degrade and ultimately destroy" the so-called Islamic State group, White House spokesman Josh Earnest said in explaining why Mr. Obama wants a new AUMF.
Mr. Obama is expected to send his preferred text to Congress this week, and possibly as early as Wednesday.
Last week, the Islamic State, also known as ISIL or ISIS, claimed that Kayla Mueller, a U.S. citizen and aid worker it held, was killed when warplanes bombed the building in Raqqa, the group's de facto capital in Syria. Jordanian F-16s, escorted by U.S. F-22s, were reported to have conducted a series of strike on the town following the burning alive of a Jordanian pilot who was captured by the group after he crashed in Syria in December.
On Tuesday, both the White House and Ms. Mueller's family confirmed that she was dead, although the details of when and how she died weren't released.
Mr. Obama has also sent 3,000 troops back to Iraq. He insists they won't engage in combat operations.
The current AUMF was passed by Congress, which has authority under the Constitution to authorize war, on Sept 14, 2001. It gave then-president Bush authority to "use all necessary and appropriate force against those nations, organizations, or persons he determines planned, authorized, committed or aided the attacks that occurred on September 11, 2001."
The force authorization was clearly aimed at al-Qaeda and the Taliban, which then controlled Afghanistan, and Mr. Obama has stretched it AUMF to wage war against the Islamic State group in Iraq and Syria.
The extremists control a swath of Iraq and Syria more than three times the size of southern Ontario. The group has declared a nascent caliphate led by Abu Bakr al-Baghdadi, who broke with al-Qaeda a year ago, making the legality of the current AUMF being used by Mr. Obama to authorize attacking the group even more tenuous.
Unlike the open-ended authority given Mr. Bush, the authorization Mr. Obama is reportedly seeking would provide a three-year mandate for the war against the so-called Islamic State. That would leave Mr. Obama's successor with an expiring AUMF in early 2018, roughly a year after taking office.
Published reports also say Mr. Obama's preferred version would severely limit ground troops, while allowing for those the President has already sent.
While there is broad support in Congress for attacking the Islamic State extremists, anything regarded as an effort by Mr. Obama to bind the hands of his successor will be vigorously opposed by Republicans.
Ohio Republican John Boehner, speaker of the House of Representatives, said he expects lengthy hearings before a vote in the spring. It's "going to be incumbent upon the President to go out there and make the case to the American people for why we have to fight this fight," he said.
Even Mr. Obama's allies, Democrats who back a new AUMF, don't want the sort of open-ended licence passed in haste after the 2001 terrorist attacks. "What would be the length of time … what would be the … extent of geography, what is the scope of the authorization?" Nancy Pelosi, the California Democrat who is minority leader in the House of Representatives, told NBC.
Senator Orrin Hatch, a Republican from Utah, wants the new AUMF to be sufficiently broad so it can be used not only against the Islamic State group but also against associated or successor groups of jihadis.
"Most importantly, the authorization should not impose any artificial and unnecessary limitations such as those based on time, geography and type of force that could interfere with our strategic objective of defeating Islamic State," Mr. Hatch said.