Unlike many of the pieces of legislation I considered as a member of the House of Representatives from 1995 to 2003, the joint resolution I and 419 of my then-colleagues voted for on Sept. 14, 2001, was short and straight-forward. The authorization for the use of military force (AUMF), signed into law four days later by President George W. Bush, was limited in time and scope. It allowed the United States to take military action against those individuals, governments and organizations responsible for the terrorist attacks of Sept. 11, 2001.

That goal was accomplished long ago. Yet here we are, 18 years later, and that single authorizing paragraph is once again being considered as legal justification for using American armed forces; this time possibly against Iran.

The dogged longevity of the AUMF is a towering example of how, in this 21st century, the Congress largely has abdicated any responsibility to determine our nation’s conduct of international affairs, especially when those actions involve matters of national security and the military.

While Congress may from time to time become quite vocal in critiquing a president’s handling of national security matters, when push comes to shove, members of both houses of the Congress fall largely silent; and in so doing, permit the president to engage our nation’s armed forces based on the flimsiest of legal authority, if any.

The AUMF was considered and passed by the Congress in the immediate aftermath of 9/11. It was unquestionably justified by the horrendous terror attacks on that date. Specifically, the Resolution authorized the president to use whatever means he deemed necessary, including military force, “against those nations, organizations, or persons he determines planned, authorized, committed, or aided the terrorist attacks that occurred on September 11, 2001, or harbored such organizations or persons.”

Actions by the Bush and Obama administrations against Osama bin Laden and al Qaeda in Afghanistan and elsewhere, including the killing of bin Laden in 2011, legitimately were undertaken pursuant to the authorities set forth in the AUMF.

Things become far murkier, however, when considering that a wide range of other actions by those two presidents and the current president, have been justified by that same authorization; notwithstanding the absence of any actual or even colorable link to those who “planned, authorized, committed, or aided the terrorist attacks that occurred on September 11, 2001.”

And it is not just one president after another who cites the AUMF as legal authority for actions ranging from warrantless surveillance against American citizens, to cruise missile attacks on Syrian government air bases, and actions against ISIS throughout the Middle East region. Members of Congress queue up for media interviews when called upon to voice support for such policies by Presidents Bush, Obama and Trump, and routinely cite the AUMF in defense of presidential undertakings with which they agree.

In its defense, the Congress has not been completely somnambulant in the face of presidents claiming authority in the AUMF that clearly isn’t there. There have been several pieces of legislation introduced in these intervening years that would limit or repeal the 2001 legislation; but none has come near to securing a majority of votes in either house.

Defenders of expansive executive power have not been napping either. In 2018, Sens. Bob Corker (R-Tenn.) and Tim Kaine (D-Va.) tried to convince the Senate that the 2001 AUMF needed to be updated and actually expanded, so as to give U.S. presidents authority to deploy America’s armed forces against any entities or individuals determined by the commander in chief to be “associated” with known terrorist organizations. The wording of this resolution truly would have resulted in a perpetual grant of war-making power to future presidents; without any pretense whatever of limiting the authority temporally.

All this is not to argue that a president’s ability to deploy American military might with flexibility and dispatch should be strictly limited. Being able to act swiftly and decisively to protect our national security interests in myriad and often unforeseen situations around the world, is the essence of presidential responsibility. But doing so under color of legislative authority never designated for such actions, undermines respect for the rule of law and for the credibility of government actions generally.

When Congress sits back, and by inaction allows presidents repeatedly to ignore and abuse both the letter and the intent of laws like the AUMF, the system of checks and balances so carefully and deliberately crafted into our Constitution is undermined significantly. And power once ceded by the Congress to the president is not easily recaptured, if ever.