President Biden has chosen an apt date, the 20th anniversary of 9/11, to complete the withdrawal of American forces from Afghanistan. Congress should do its part by commemorating another anniversary—September 14, 2001, the date on which the AUMF for the inchoate “war on terror” was passed—by withdrawing that authority. The loose and hasty AUMF, which legislators like Senator Tim Kaine of Virginia have challenged—with signals of interest from the White House—has been used to justify military operations far removed from 9/11, al Qaeda, or Afghanistan. It has become a blanket authority for any operation nominally connected with terrorism.
Repealing the AUMF—and entertaining replacements only if they are carefully defined and time-limited—would prevent mischief. But it would be a constitutionally significant moment because it would involve Congress formally reclaiming its war powers. This is an excellent, controlled constitutional test. It could require Democrats to defend their branch of government against a president of their own party. Even better, it could entail a president ceding authority. We typically think of presidential strength in terms of protecting and amplifying the power of the office. Congress passing, and the president signing, a repeal would instead be a historic instance of constitutional fortitude.