(Tolga Bozoglu/EPA)

Jack Goldsmith is a professor at Harvard Law School and a senior fellow at the Hoover Institution. Ryan Goodman is a professor at New York University Law School. Steve Vladeck is a professor at American University Washington College of Law. Goldsmith contributes to the Lawfare blog; Goodman and Vladeck edit the Just Security blog.

President Obama has stated that he wants “to begin engaging Congress” over a new Authorization for Use of Military Force (AUMF) against the Islamic State and also that he wants to “right-size and update” the 2001 AUMF “to suit the current fight, rather than previous fights.” It appears that Congress, too, is finally getting serious about putting U.S. counterterrorism operations on a contemporary and more rigorous statutory footing.

There are many politically contested questions about how the government should accomplish these goals — about, for example, whether U.S. ground troops should be banned from Syria and Iraq, how the fight against the Islamic State should be conducted consistent with U.S. policy against Syrian dictator Bashar al-Assad and what rules should govern the targeted killing of U.S. citizens abroad. There are also tricky questions of timing and form — whether, for example, Congress should take up an AUMF against the Islamic State separately from or in conjunction with the right-sizing of the 2001 AUMF against al-Qaeda and the Taliban, and whether the lame-duck Congress or the new one should address these issues. We differ among ourselves on some questions. We nonetheless believe that, however they are resolved, an important foundational consensus can be reached — across branches and parties — on five core principles that should guide any new or revised authorization of force related to counterterrorism.

Specify the enemy. A new AUMF should identify which groups the United States is fighting and specify the general objectives of the mission. At a minimum, the identified groups would include the Islamic State, as well as al-Qaeda and the Taliban if the 2001 authorization was updated in conjunction with a new authorization for the Islamic State.

Make international law applicable. Any new AUMF should be limited, at a minimum, by governing international law with respect to sovereignty (and thus the places where the president can use force) and the conduct of warfare. This limitation would mean, for example, that the United States could operate in Iraq and Afghanistan because those countries have consented. It would also permit force to be used in Syria to the extent international law permits, as the administration currently claims it does, either in self-defense of Iraq or, much more controversially, because Syria is unwilling or unable to mitigate threats against the United States emanating from its borders. And the limitation would make clear that the United States could not use force in a country simply because members of al-Qaeda or the Islamic State are found there.

Increase transparency. Neither Congress nor the American public has a clear idea whom the United States is fighting or where, especially when it comes to forces associated with al-Qaeda. Any new AUMF should require the president to identify the groups against which force is used, along with related details, regularly in a report to Congress and, unless strictly required by national security, the American people. The president should also share with Congress, and the public to the extent possible, the administration’s legal rationales for using force. Such transparency rules should also be imposed on the 2001 AUMF if it is not incorporated into the new one. Congress should also consider imposing these transparency requirements on uses of force against terrorists under the president’s Article II powers.

Sunset all AUMFs. Any new AUMF should be set to expire in 2017. If the 2001 AUMF is not folded into the AUMF for the Islamic State, Congress should separately determine that the 2001 AUMF should sunset in 2017 as well. A 2017 sunset provision does not necessarily indicate that the armed conflict against the specified terrorist groups will be over then. Rather, it will simply force the next Congress and president to decide after several years of experience whether and how the authorizations should be updated, or whether, if conditions warrant, they should be allowed to expire.

Repeal old AUMFs. Once force is expressly authorized against the Islamic State, the 2002 AUMF for Iraq will be unnecessary. The 2001 AUMF can also be repealed if al-Qaeda and the Taliban are folded in to the AUMF for the Islamic State.

These five principles emerged from independent proposals recently put forward by two groups of legal experts, whose members included former senior government lawyers in the George W. Bush and Obama administrations. If the principles became law, they would give the president all of the authorities he needs to conduct the current armed conflicts against terrorist organizations, give those armed conflicts Congress’s contemporary imprimatur, ensure that we do not slide into endless war without deliberation and choice, and do away with unnecessary military authorities. The president and Congress should be able to agree on at least this much.