Top lawyer signals Obama administration flexibility on 2001 Authorization to Use Military Force against al-Qaida, central to current war on the Islamic State

The Pentagon’s top lawyer suggested on Friday that the Obama administration would accept “refinements” to a seminal 2001 counter-terrorism law if Congress passes a stalled White House initiative to legally bless its war against the Islamic State.

While backing further away from Barack Obama’s 2013 call to “ultimately repeal” the 2001 Authorization to Use Military Force (AUMF), Stephen Preston, the Defense Department general counsel, continued to assert that Isis’s very public split from al-Qaida is a legally insignificant fact – an argument useful to the administration as it wages a war in Iraq and Syria that Congress shows little sign of endorsing, nine months on.

“The name may have changed, but the group we call Isil today has been an enemy of the United States within the scope of the 2001 AUMF continuously since at least 2004,” according to the prepared text of Preston’s speech to the American Society of International Law.

For over a year, al-Qaida and Isis have been locked in a vicious struggle for control of the global Salafist jihadist movement. By all available metrics – adherents, allegiance from regional jihadist groups, funding, territory, propaganda – Isis is routing al-Qaida. Rumors are now circulating that al-Qaida leader Ayman Zawahiri might even disband the organization that knocked down the World Trade Center.

Yet because the administration can trace Isis’s origins to al-Qaida’s Iraqi franchise during the 2003-2011 US occupation, it has argued for months that what Preston called the “recent split” between Isis and al-Qaida has no bearing on the US’s legal authorities to attack Isis, even though Congress has never approved war, and Obama’s unilateral authorities under the War Powers Act have long since expired.

Earlier this year, Obama submitted a draft authorization for the current anti-Isis war to Congress. That draft, to the disappointment of some Democratic legislators, rejected a proposal to phase out the 2001 law, a move heralded by Preston’s May 2014 congressional testimony backing away from Obama’s call for repeal the previous year.

But Congress has not voted for the new war authorization, and lawmakers indicated their skepticism toward it during several rounds of administration testimony. Without it, the administration’s arguments for the legality of the war rely heavily on the 2001 authorization of war against Isis’s enemy, al-Qaida.

Nodding to skeptics, Preston conceded “we would be having a different conversation if Isil had emerged out of nowhere a year ago”.

But Preston also suggested to those dissatisfied with the administration’s retention of the 2001 AUMF that it would at least modify the 14-year old law – but only after Congress passes the new anti-Isis authorization.

“The president has made clear that he stands ready to work with Congress to refine the 2001 AUMF after enactment of an Isil-specific AUMF,” Preston said, using another acronym for Islamic State.

Even though Obama specifically rejected twinning the end of the 2001 AUMF with passage of an anti-Isis one, Preston on Friday suggested that an anti-Isis AUMF “might also create a model to guide future efforts to refine the 2001 AUMF or otherwise authorize the use of force against some new threat we may not yet foresee”.

Beyond Isis and al-Qaida, Preston insisted that the drawdown of troops in Afghanistan, which Obama has portrayed as an end to the Afghanistan war, also has no bearing on the relevance of the 2001 AUMF that launched the war.

“The enemy has not relented, and significant armed violence continues,” Preston said, calling US operations in Afghanistan “substantial”, even though Obama often tells the American people that the US combat role in Afghanistan is over.

While Preston nodded to Obama’s 2013-era rejection of a “perpetual war footing”, he not only defended the sweeping powers provided by the 2001 AUMF but also offered no guidance for determining how the US would know they are no longer necessary.

“The US constitution,” Preston noted, “says nothing directly about how wars are to be ended.”