The need is especially compelling, given the way in which the 2001 AUMF has been transformed since its enactment. When it was passed in late September 2001, it granted President George W. Bush the limited authority to target “nations, organizations, or persons” who “aided” in the attacks on the Pentagon and World Trade Center. Despite the passion and patriotism of the moment, Congress explicitly turned down Bush’s request for the sweeping authority “to deter and pre-empt any future acts of terrorism … against the United States.”

Nevertheless, executive-branch lawyers under Presidents Bush and Obama reinterpreted the narrow language of the 2001 AUMF to provide the sweeping power to preempt future attacks which Congress explicitly denied the presidency in 2001. ISIS, for example, can only be traced back to a group that came into existence in 2003—and yet Obama didn’t get a new authorization from Congress when he began his war against it in 2014.

The new resolution not only fills this gap, but requires Congress to take responsibility for presidentially initiated wars against other terrorist groups operating in Afghanistan, Iraq, Syria, Somalia, Libya, and Yemen—specifically authorizing the president to designate the Nusra Front, al-Shabab, al-Qaeda in the Arabian Peninsula, and the Khorasan Group as legitimate military targets. Of course, the merits of each of these initiatives is open to serious argument, and Congress may well impose new conditions on each or all of these authorizations as the debate moves beyond the Senate Committee.

The real problem with the AUMF involves the way it enables Trump to launch new wars against poorly defined “terrorist groups” in the years ahead. Key provisions of Flake-Kaine destroy the system of checks and balances that Congress put into place in 1973 to safeguard its constitutional role as the ultimate authority over the question of war and peace.

During the Vietnam War, Richard Nixon directly challenged this authority—asserting that he could continue the Vietnam War even after Congress had repealed the Gulf of Tonkin Resolution. Leaders of both parties responded with the War Powers Resolution, mustering the two-thirds majorities required to overcome a presidential veto. The War Powers Resolution created a new system of checks and balances to make it impossible for the commander-in-chief to make Nixonian claims in the future. It required presidents to gain congressional consent within 60 days of their decision to initiate hostilities; and if they failed to convince the House and Senate that their war was justified, they were obliged to withdraw their forces from the field within the next 30 days.

The Flake-Kaine proposal would release President Trump from this burden. It would allow him to designate a new terrorist group as a military target, and continue his war against it so long as Congress fails to vote to override that decision within 60 days. If both the House and Senate fail to veto the new venture within this short deadline, Trump could continue his war for the rest of his term—and potentially to expand it to those he designates as terrorists in Africa, Asia, or even Latin America.