If the decline of the original al Qaeda network and the decline of U.S. interest in the Afghan Taliban were the only considerations, one might applaud rather than fret over the declining relevance of the AUMF. There is, however, a third consideration: significant new threats are emerging, ones that are not easily shoehorned into the current AUMF framework.

To a considerable extent, the new threats stem from the fragmentation of al Qaeda itself. In this sense, the problem with the original AUMF is not so much that its primary focus is on al Qaeda, but rather that it is increasingly difficult to determine with clarity which groups and individuals in al Qaeda’s orbit are sufficiently tied to the core so as to fall within the AUMF. And given the gravity of the threat that some of these groups and individuals may pose on an independent basis, it also is increasingly odd to premise the legal framework for using force against them on a chain of reasoning that requires a detour through the original, core al Qaeda organization.

The fragmentation process has several elements. First, entities that at least arguably originated as mere regional cells of the core network have established a substantial degree of organizational and operational independence, even while maintaining some degree of correspondence with al Qaeda’s leaders. Al Qaeda in the Arabian Peninsula (AQAP) is a good example. Al Qaeda in Iraq (AQI) arguably fits this description as well, though in that case one might point to a substantial degree of strategic independence as well.