Carolyn Kaster/AP

On Wednesday, just over six months after bombs started falling again in Iraq, the White House sent to Capitol Hill the three-page document that Republicans and Democrats had long been clamoring for: a proposed resolution formally authorizing the use of military force against the Islamic State. And just as soon as lawmakers read the draft's 225 war-making words, they began picking them apart.

Speaker John Boehner, who had personally and repeatedly demanded that the president submit his proposal, complained that the text's limitation on ground troops constrained the military. Representative Chris Van Hollen, one of Obama's closest allies in the House, said it was "too broad in scope." Senator Tim Kaine, who was the president's hand-picked Democratic Party chairman in 2009, cited concerns about its "vagueness." And on, and on.

The White House proposal could set off the most significant congressional war debate in more than a decade, since lawmakers signed off in 2002 on the last Iraq war under President George W. Bush. President Obama's last attempt, in 2013, to get buy-in from Capitol Hill for military action against the Bashar al-Assad regime in Syria did not go well: The request didn't get a vote in either the House or Senate and was soon pre-empted by a deal in which Assad promised to destroy his chemical weapons.

And despite the pleas from lawmakers for a vote on the ISIS resolution, there's no guarantee it will get that far. Boehner told reporters the House will take its time on the resolution, with hearings, revisions, and extensive debate. "This is the beginning of a legislative process, not the end," he said Wednesday. As Uri Friedman noted last month, despite the public demands for a proposal and a strategy from Obama, lawmakers haven't exactly rushed to take ownership of the war. The White House isn't showing much urgency, either. After all, the military campaign in Iraq and Syria began last summer and will continue whether Congress acts or not, and the administration isn't backing off its claim that the war is legal under the authorizing resolution that was enacted in 2001 after the 9/11 terrorist attacks. One early point of debate in the new proposal is that while the draft repeals the 2002 authorization of force in Iraq, it leaves in place the 2001 resolution that first launched the war on terror. Representative Adam Schiff, the top Democrat on the House Intelligence Committee, noted that because of that loophole, the three-year expiration in the Obama proposal was effectively meaningless.

Rather than argue congressional approval is necessary to continue the ISIS operation, Obama spokesman Josh Earnest said it was important for lawmakers to exercise their responsibility in the area of national security and "make their voices heard." The president, in his own letter to Congress accompanying the proposal, wrote that enactment of the resolution would be a show of national unity.

I can think of no better way for the Congress to join me in supporting our nation's security than by enacting this legislation, which would show the world we are united in our resolve to counter the threat posed by ISIL.

Republicans want Obama to make an aggressive public case for the resolution, although that request is probably aimed at securing enough Democratic votes to overcome opposition in their own party. The president began by making a brief statement at the White House on Wednesday afternoon, citing progress in the mission to date while arguing that his draft struck the right balance. "It is not the authorization of another ground war, like Afghanistan or Iraq," he said. At the same time, he defended its lack of geographic restrictions, saying commanders needed "the flexibility" to target ISIS leaders wherever they might be.

Speaking at the White House on Wednesday, Earnest acknowledged that the president's proposal was "a starting point" and would likely change.  Republicans and Democrats will haggle over the wording prohibiting "enduring offensive ground combat operations." Congress also could tweak the three-year sunset period, or add some geographic restrictions on military operations where there now are none. And that would be appropriate. A good deal of the hand-wringing over Congress's role in the fight against ISIS can be traced to what is now seen as the headlong rush to war in Iraq 12 years ago. Democrats in particular want to demonstrate they've learned that lesson by closely scrutinizing—and possibly altering—a request from a president of their own party. The White House is cognizant of this, and the resolution has likely been drafted knowing that Congress will want to put its own stamp on it.

The forthcoming debate may not determine how many more troops are sent off to war, or how many more airstrikes Obama orders in the Middle East. But the stakes remain high nonetheless, and not just for the president. While Congress has and will remain the butt of jokes regardless of the outcome, whiffing on a war resolution would set a new low for legislative prestige. This is a challenge that leaders of both parties demanded. Now we'll see if they can meet it.

Proposed AUMF

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