Jens David Ohlin is a professor of international law at Cornell University Law School. He is a co-editor of “Targeted Killings: Law and Morality in an Asymmetrical World” and co-author of Defending Humanity:

When Force is Justified and Why.” In the matter of al-Qaeda jettisoning the Islamic State of Iraq and Syria, Ohlin says the U.S. must now find an independent rationale before targeting ISIS members.

Ohlin says:

“The United States is engaged in an armed conflict with al-Qaeda, and under international law, the US military is permitted to target individuals based on their membership in al-Qaeda. This raises the fundamental question of what counts as al-Qaeda. The organization is no longer unified in a single command structure, but instead is a loose network of local affiliates.

"Recently, the top al-Qaeda leadership disavowed its affiliate in Syria and Iraq, also known as Islamic State of Iraq and Syria. Presumably the disavowal stemmed from the refusal of the local chapter to follow central commands. If this disavowal is based on reality (as opposed to opportunistic rhetoric), then it means that the U.S. needs to assert an independent rationale under international law for targeting members of ISIS.

“The simplest answer is to remove the question from the White House, and to get Congress to pass a new Authorization for Military Force that explicitly lists the groups that America is at war with. Right now, the White House is still operating under the authorization that was passed in the immediate aftermath of 9/11.

“But I wouldn’t hold my breath that Congress will wade into these muddy waters any time soon.”

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