Two senators are urging Congress to vote for an official authorization to fight against ISIS

Two US senators announced Thursday that they will introduce a new bill to authorise military force to fight ISIS on Friday.

Republican Senator Jeff Flake and Democrat Senator Tim Kaine will introduce an authorization for the use of military force (AUMF) against ISIS, al-Qaeda and the Taliban.

The proposed AUMF would be the first since Sept. 18, 2001, when Congress gave former President George Bush authorization to “use all necessary and appropriate force against those nations, organisations, or persons he determines planned, authorised, committed, or aided the terrorist attacks that occurred on September 11, 2001, or harbored such organisations or persons, in order to prevent any future acts of international terrorism against the United States by such nations, organisations or persons.”

According to the US Constitution, only Congress has the authority to declare war. The executive branch thereafter has the power to direct the military as commander-in-chief.

Flake and Kaine also introduced an AUMF against ISIS in 2015, but it failed to pass the Senate.

“I get it, members of Congress are afraid to cast a vote on war,” Kaine said after the 2015 bill failed. “If you want to be real cold about it, if Congress doesn’t support it, then we shouldn’t be forcing people to risk their lives.”

The Obama administration had been using the 2001 AUMF to justify airstrikes against ISIS and other terrorist groups. His reasoning behind this was that, since ISIS was al-Qaeda’s affiliate in Iraq from 2004 to 2014, the executive branch has authority to go to war with any group that has ever been allied with al-Qaeda.

But many legal experts were quick to criticise Obama’s legal reasoning.

“This is a weak argument,” Cornell University Law School professor Jens David Ohlin said in 2014. “Yes, ISIS once had a relationship with al-Qaeda and Osama Bin Laden, but that prior relationship no longer governs. What matters is the current relationship.”

The 2001 AUMF “does not plausibly extent to ISIL,” Cardozo School of Law’s Deborah Pearlstein also said at the time. Many other legal scholars struck a similar tone.

It should be noted that, while Obama used the 2001 AUMF to fight ISIS, he also sought Congress’ approval for a new AUMF.

“If Congress believes, as I do, that we are at war with ISIL,” Obama said in 2015, “it should go ahead and vote to authorise the continued use of military force against these terrorists.” The bill failed.

NOW WATCH: Trump approved the largest weapons deal in US history — here’s what Saudi Arabia is buying

Business Insider Emails & Alerts

Site highlights each day to your inbox.

Follow Business Insider Australia on Facebook, Twitter, LinkedIn, and Instagram.