During a White House press briefing last week, Deputy National Security Adviser Ben Rhodes was clear on the administration’s ultimate goal with regard to the Islamic State: "Absolutely, in the long term our objective would be to see an organization like ISIL defeated," said Rhodes.

He wasn't the only administration official pledging the group's ultimate destruction. "ISIL must be destroyed/will be crushed"  tweeted Secretary of State John Kerry last Thursday, one day after President Obama called the group a "cancer" with "no place in the 21st century."

The administration’s long term goal is clear. But what specific policies are experts saying should be used to achieve it?

As Washington’s national security elites both inside and outside government scramble to provide policy prescriptions, two things have become startlingly clear: the situation in Iraq has changed faster than almost anyone expected. And there’s little to no consensus on how the United States should respond. Policies pushed by think tank experts, former government officials, and op-ed columnists have ranged from complete disengagement to boots-on-the-ground intervention. Here’s our list of the most noteworthy policy suggestions from Washington’s strategic intelligentsia, from the hands-off to the full-on.

Policy: Limited airstrikes, regional diplomacy, and an incremental rollback of Islamic State fighters

Who’s pushing it: Brian Katulis, Hardin Lang and Vikram Singh at The Center for American Progress

What it means: Published in June almost two months before strikes against the Islamic State began, a report by the left-leaning Center for American Progress comes closest to describing what the Obama administration’s strategy has been so far. It stresses the need to tie US military support to Iraqi leaders’ ability to form an inclusive government, and pushes the importance of reinforcing regional U.S. allies like Jordan and Turkey. The report advocates for the use of targeted military force, writing that “the United States should prepare for limited use of U.S.—and if possible allied—air power on Islamic State targets to degrade their ability to further destabilize the country and to protect U.S. interests.” In other words, CAP predicted President Obama’s initial policy response to the Islamic State months before he authorized it.

Policy: Strike Islamic State forces in Syria, even if it helps Assad

Who’s pushing it: Max Abrahms, Northeastern University

What it means: A growing number of officials and scholars have expressed the belief that any strategy aimed against the Islamic State in Iraq must also take into account the group’s presence in Syria. “Can [the Islamic State] be defeated without addressing that part of the organization that resides in Syria?” said Chairman of the Joint Chiefs of Staff Gen. Martin Dempsey during a Thursday press conference. “The answer is no.”

As BuzzFeed has reported, some scholars like Northeastern University terrorism expert Max Abrahms have even floated the idea of a U.S. alliance with Bashar al-Assad to fight and weaken Islamic State forces within Syria. “It makes obvious sense in my mind, if the U.S. is going to side with the militants or with Assad, for us to side with Assad,” Abrahms told BuzzFeed. While “the enemy of our enemy” might in time become our friend, the Obama administration is unlikely to partner publicly with a regime it has so fiercely condemned in the past.

Policy: Put combat troops on the ground, boost special ops and increase airstrikes

Who’s pushing it: Max Boot, Senior Fellow at The Council on Foreign Relations

What it means: In an August 16th column for The Spectator, Boot advocates for a significantly expanded military presence and mission scope in Iraq. “Defeating ISIS will require boosting the western advisory and special operations presence in Iraq to somewhere in the neighbourhood of 10,000 to 15,000 personnel and sending aircraft that will be based in Iraq...to facilitate a more sustained bombing campaign,” Boot writes. Though Boot pushes President Obama and British Prime Minister David Cameron “to act unless they want to leave a new terrorist state as part of their legacy in office,” Obama has repeatedly ruled out the use of combat troops on the ground, and the British have no current military presence in the country.

Policy: Fight only if the U.S. has the political consensus at home to do so, anything less is unsustainable and cannot succeed

Who’s pushing it: Brian Fishman, Counterterrorism Research Fellow at The New America Foundation

What it means: In an August 20th piece for the blog War on the Rocks, Fishman argues that no policy of rolling back the Islamic State's geographical gains, or arming its enemies can be considered a sustainable "fix" for the problem posed by the group. "A policy of pushing [the Islamic State] into a smaller box does not solve the problem; it is a temporary fix, an open-ended commitment, an invitation for mission creep, or all of the above," writes Fishman. According to Fishman, the U.S. mission against the Islamic State group and the probability for that mission's success are fundamentally tied to America's political will in the Middle East and its capacity to do what it may ultimately take to defeat the group. As Fishman wrote:

"War is a matter of matching ends, ways, and means – including political and popular support. It would therefore be irresponsible to support a policy that would require a level of commitment that our political institutions do not possess. Our discourse is too broken. Short of a major terrorist attack, our leaders do not have the ability to produce consensus. And without real national consensus to sustain a strategy, there is no viable mechanism to defeat ISIL."

And so the scale of fight against the Islamic State may ultimately hinge as much on domestic politics as it does military force.