President Obama waived a provision of federal law designed to prevent the supply of arms to terrorist groups to clear the way for the U.S. to provide military assistance to "vetted" opposition groups fighting Syrian dictator Bashar Assad.

Some elements of the Syrian opposition are associated with radical Islamic terrorist groups, including al Qaeda, which was responsible for the Sept. 11 attacks in New York, Washington, D.C., and Shanksville, Pa., in 2001. Assad's regime is backed by Iran and Hezbollah.

The president, citing his authority under the Arms Export Control Act, announced today that he would "waive the prohibitions in sections 40 and 40A of the AECA related to such a transaction."

Those two sections prohibit sending weaponry to countries described in section 40(d): "The prohibitions contained in this section apply with respect to a country if the Secretary of State determines that the government of that country has repeatedly provided support for acts of international terrorism," Congress stated in the Arms Control Export Act.

"For purposes of this subsection, such acts shall include all activities that the Secretary determines willfully aid or abet the international proliferation of nuclear explosive devices to individuals or groups or willfully aid or abet an individual or groups in acquiring unsafeguarded special nuclear material," the law continues.

The law allows the president to waive those prohibitions if he "determines that the transaction is essential to the national security interests of the United States."

Under section 40(g) of the AECA, the Obama team must also provide Congress — at least 15 days before turning over the weapons — "the name of any country involved in the proposed transaction, the identity of any recipient of the items to be provided pursuant to the proposed transaction, and the anticipated use of those items," along with a list of the weaponry to be provided, when they will be delivered, and why the transfer is key to American security interests.

Sen. Bob Corker, R-Tenn., and Sen. Carl Levin, D-Mich., endorsed providing military assistance to the Syrian opposition during an appearance on CBS' "Face the Nation" Sunday.

"Our intelligence agencies, I think, have a very good handle on who to support and who not to support," Corker said. "And there's going to be mistakes. We understand some people are going to get arms that should not be getting arms. But we still should be doing everything we can to support the free Syrian opposition."

UPDATE: White House releases statement on waiver

National Security Council spokesman Caitlin Hayden issued the following statement concerning the president's actions with regard to waiving certain controls on military aid in the Syrian crisis:

"This action will allow the U.S. Government to provide or license, where appropriate, certain non-lethal assistance inside or related to Syria. This includes: 1) chemical weapons-related personal protective equipment to international organizations, including the Organization for the Prohibition of Chemical Weapons, for the conduct of their operations; 2) chemical weapons-related life-saving assistance for organizations implementing Department of State or U.S. Agency for International Development programs to strengthen local Syrian health care providers’ ability to prepare for and respond to any use of chemical weapons; and 3) defensive chemical weapons-related training and personal protective equipment to select vetted members of the Syrian opposition, including the Supreme Military Council, to protect against the use of chemical weapons. This action is part of longstanding and ongoing efforts to provide life-saving chemical weapons-related assistance to people in need in Syria."