I am not a legal scholar, and am sure that skilled lawyers could make good arguments on either side for the legality of the Obama administration ‘s current use of force against IS without Congressional authorization. Yet even though I take a fairly expansive view of a president’s Article II authority as commander-in-chief, a combination of prudence, politics, and policy all point towards the merit of seeking Congressional support.

Even before the Islamic State’s resurgence, some national security legal scholars were arguing that the Obama administration ‘s campaign against al Qaeda and its proliferating franchises was skating on increasingly thin legal ice. For our academically-inclined readers, my Strauss Center and University of Texas faculty colleague Bobby Chesney last year published a compelling argument in the Michigan Law Review on the growing obsolescence of the 2001 Authorization to Use Military Force (AUMF) and the need for a new AUMF. In light of ongoing U.S. airstrikes in Iraq, Chesney and his colleagues at the indispensable Lawfare blog are making similar arguments this week on the need for Congressional authorization for our current operations.

Substantively, a new AUMF, especially focused on IS and its affiliates, could take into account the evolution and adaptation of militant jihadist groups in the 13 years since the Sept. 11 attacks, as well as the shifts and drawdowns of American ground force deployments in Afghanistan and Iraq. The Islamic State’s nihilistic wickedness may be generating the headlines now, but over time even more danger may be posed by its magnetism towards other al Qaeda franchises and its potential leadership of militant jihadist groups spanning the broader Middle East and points beyond in Africa and South Asia.