WASHINGTON — The White House's delivery of a measure that would authorize a "limited" Islamic State fight marked the start of what should be an uncertain journey on Capitol Hill.

The resolution strikes a measured tone about the scope of America's newest war against violent Islamic groups from its first line: "To authorize the limited use of the United States Armed Forces against the Islamic State of Iraq and the Levant."

The White House's version of the authorization of the use of military force includes several notable — and likely controversial on the Hill — provisions.

One is a statement about that the nature of the threat the Islamic State poses to the United States.

The AUMF says the group "poses a grave threat to the people and territorial integrity of Iraq and Syria, regional stability, and the national security interests of the United States and its allies and partners."

What it does not say likely will draw the ire of hawkish Republicans in the House and Senate: that the Islamic State poses a direct threat to the United States.

But in a letter to Congress accompanying the joint resolution, President Barack Obama writes that "if left unchecked, [the Islamic State] will pose a threat beyond the Middle East, including to the United States homeland."

The White House's measure does note the group has "stated that they intend to conduct terrorist attacks internationally, including against the United States, its citizens, and interests."

Still, since Republicans control both chambers, it is possible the GOP chairmen of the House Foreign Affairs and Senate Foreign Relations committees will add language calling the group a direct threat before any possible floor votes.

The draft AUMF would authorize the president "to use the armed forces of the United States as the president determines to be necessary and appropriate against [the Islamic State] or associated persons or forces."

As expected, the White House is proposing language that would limit the kinds of missions US forces could conduct in the Islamic State fight, and how long it can go on.

The legislation "does not authorize the use of the United States armed forces in enduring offensive ground combat operations."

In the accompanying letter, Obama explicitly notes his draft AUMF "would not authorize long-term, large-scale ground combat operations like those our Nation conducted in Iraq and Afghanistan."

"Local forces, rather than U.S. military forces, should be deployed to conduct such operations," Obama wrote, adding his version proposes "the flexibility" for US ground forces to do "limited" missions.

That list includes "rescue operations involving US or coalition personnel or the use of special operations forces to take military action against [Islamic State] leadership," Obama tells members.

"It would also authorize the use of US forces in situations where ground combat operations are not expected or intended, such as intelligence collection and sharing, missions to enable kinetic strikes, or the provision of operational planning and other forms of advice and assistance to partner forces," Obama writes.

Senate Armed Services Committee Chairman Sen. John McCain, R-Ariz., told reporters Tuesday it is unclear who would be the judge of what constitutes an "enduring" and "offensive" ground combat operation.

McCain echoed many other GOP members when he expressed concerns about passing any AUMF for an armed conflict that places such restrictions on a commander in chief.

McCain told reporters he would view that kind of language as "unconstitutional," saying the Constitution gives the president the power to run the country's armed conflicts.

His comments offer a preview of just one of the coming AUMF fights because most Democrats support language that limits another large US military ground operation in the Middle East.

The White House also proposes sun-setting the AUMF after three years, unless Congress reauthorizes it.

Another point of debate in coming months as both chambers work on potentially competing versions will be the lack of any geographic limitation in the White House's measure.

Senate Foreign Relations Committee Chairman Sen. Bob Corker, R-Tenn., said the panel will begin its work on an AUMF promptly. That will include public hearings following a long-planned recess next week.

"We have a week of recess before we can even start. I think the language, of course, is important, but where a lot of time is going to be spent is understanding the plausible way forward. It's really gotten to be such a … problem, to be candid, both in Iraq and in Syriaira.

"I think there will be a good deal of time understanding the plausible way forward that they will be proposing," Corker told CongressWatch, referring to White House officials.

Asked if he expects a substantive rather than politically charged debate among lawmakers, Corker shot back: "I do. It's the most important vote a senator makes."

Still, the Foreign Relations chairman signaled some fireworks could be ahead: "I know there's really strong feelings about this issue."

House Speaker Rep. John Boehner, R-Ohio has said he wants his chamber to hold a floor debate and vote on an AUMF by the spring.

On Wednesday, Boehner told reporters that lawmakers have "an awful lot of work to do." He said he expects Congress will make "changes" but declined to discuss what those might be. "This is the start of a legislative process, not the end," the speaker said.

Privately, Senate aides say it could take the upper chamber longer to hold hearings, craft a measure that can get 60 votes, then move an AUMF to the floor.

"I don't think it would be a stretch to say the United States Senate might take a little longer than the House of Representatives," one Senate aide said.

The Senate's president pro tempore, Utah Republican Sen. Orrin Hatch, doesn't see what all the fuss about a months-long process is all about.

"I don't know why it is such a big deal," Hatch said. "We're going to give the president this kind of power and he ought to use it whenever necessary."

Combat wounded athletes from allied countries and Battalion East go head-to-head during a bronze medal game during the Marine Corps Trials, March 2015. Battalion East barely beat the allies with a final score of 22-18.
Combat wounded athletes from allied countries and Battalion East go head-to-head during a bronze medal game during the Marine Corps Trials, March 2015. Battalion East barely beat the allies with a final score of 22-18.

Lawmakers who have been vocal proponents of a new AUMF tailored for the Islamic State, including Sen. Tim Kaine, D-Va., acknowledged that members will have to weigh the fact that the US operation already is six months old. with doing its due diligence.

"I think we'll do some of both," Kaine said in a brief interview. "The most important thing is to get it right. But the delay has been unfortunate."

Secretary of State John Kerry, in a Wednesday statement, urged lawmakers to pass an AUMF, and told them US allies are watching.

"I know how committed they are to getting this right," Kerry said. "I also know from talking with so many foreign ministers all over the world that they study our debates here at home, and these public signals matter to them. The coalition itself will be stronger with passage of this AUMF."

Senate Majority Minority Leader Sen. Mitch McConnell, R-Ky., said it is "in order for Congress to debate an authorization like this."

"And because Congress must meet its responsibility to decide whether our military should use force, the Senate will review the president's request thoughtfully," McConnell said in a statement, noting GOP members will "listen closely to the advice of military commanders as they consider the best strategy."

Analysts are skeptical whether lawmakers can find enough common ground to actually pass a new AUMF, and some warn the process could do harm.

Council on Foreign Relations President Richard Haass tweeted on Wednesday morning: "be careful what you ask for: new authorization for mil force could expose lack of consensus, place limits on what US can do vs terror."

Twitter:@bennettjohnt