President Barack Obama will soon give Congress his proposal for a new authorization for the use of military force against Islamic State fighters, and it will place strict limits on the types of U.S. ground forces that can be deployed, according to congressional sources.

Almost six months after the president began using force against the Islamic State advance in Iraq and then in Syria, the White House is ready to ask Congress for formal permission to continue the effort. Until now, the administration has maintained it has enough authority to wage war through the 2001 AUMF on al-Qaeda, the 2002 AUMF regarding Iraq and Article II of the Constitution. But under pressure from Capitol Hill, the White House has now completed the text of a new authorization and could send it to lawmakers as early as Wednesday. 

If enacted, the president's AUMF could effectively constrain the next president from waging a ground war against the Islamic State group until at least 2018. Aides warned that the White House may tweak the final details before releasing the document publicly. 

In advance of the release, top White House and State Department officials have been briefing lawmakers and Congressional staffers about their proposed legislation. Two senior Congressional aides relayed the details to me. 

The president’s AUMF for the fight against Islamic State would restrict the use of ground troops through a prohibition on “enduring offensive ground operations," but provide several exemptions. First, all existing ground troops, including the 3,000 U.S. military personnel now on the ground in Iraq, would be explicitly excluded from the restrictions. After that, the president would be allowed to deploy new military personnel in several specific roles: advisers, special operations forces, Joint Terminal Attack Controllers to assist U.S. air strikes and Combat Search and Rescue personnel.

Under the president’s proposal, the 2002 AUMF that was passed to authorize the Iraq war would be repealed, but the 2001 AUMF that allows the U.S. to fight against al-Qaeda and its associated groups would remain in place.

The new statute would authorize military action against Islamic State and its associated forces, which are defined in the text as organizations fighting alongside the jihadists and engaged in active hostilities. This means the president would be free to attack groups such as the al-Nusra Front or Iraqi Baathist elements who have partnered with the Islamic terrorists in Syria or Iraq. There are no geographic limitations, so the administration would be free to expand the war to other countries.

The president’s proposed AUMF would sunset in three years and would not give the president the unilateral authority to extend the authorization. That means the next president would have to come back to Congress for a new authorization in 2018, if the fight against Islamic State fighters lasts that long.

The White House’s AUMF largely tracks a version introduced by Senate Foreign Relations Committee ranking Democrat Robert Menendez last December, with small tweaks to clarify the definition of Islamic State and its associated groups, and to remove the geographic limits. The president's limits on ground troops are more constricting than what some Republicans had asked for.

The president has crafted the bill so it can engender bipartisan support on Capitol Hill while still preserving an enormous amount of flexibility on the battlefield without micromanagement from Congress, one senior Republican Senate aide said. More Republicans are likely to support an AUMF now that the president has requested it formally, the aide added, warning that Republican Senator Lindsey Graham and other hawks will still object to the ground-force limitations.

Senate Majority Leader Mitch McConnell had been resisting a vote on the floor on an AUMF, but now that the president has made his move we can expect floor action in late February or early March, following hearings in the Senate Foreign Relations Committee. Some Republicans remain skeptical of the president’s actual enthusiasm for an AUMF, as the current ambiguity gives Obama a lot of flexibility in carrying out the war. They will now wait to see if the administration remains active on the issue after the legislation is introduced.

“The president has to deliver Democrat votes on this and he has to show a commitment,” the senior Republican Senate aide said. “He’s actually got to prosecute the fight to get this thing passed. If he doesn’t demonstrate that he actually wants this, you might see Republicans walk.”

The White House did not respond to a request for comment. In recent days, White House officials have acknowledged that the release of the president’s AUMF proposal is just the beginning of the effort.

“There will be a very robust debate,” White House spokesman Josh Earnest said last week. “Things that aren’t that serious have a hard time getting through the United States Congress these days. So when we’re talking about something as weighty as an authorization to use military force, I would anticipate that it will require substantial effort.”

The last time President Obama asked for an authorization to use military force, it was to strike the Assad regime in response to its use of chemical weapons. Yet it was obvious that the administration wasn’t wholly committed to actually prosecuting that war. He nixed the attacks before Congress weighed in.

This time around, Obama is already engaged in the fight against Islamic State and his team genuinely wants Congressional buy-in. Clearing up the legal ambiguity of the war will be helpful. But it won’t solve the more important conflict between the White House and lawmakers over the scale and effectiveness of the mission. 

(Updates with new details in first three paragraphs.)