Paul's amendment would in no way affect the current troop withdrawal Obama has ordered from Iraq. In October the White House announced it would begin a drawdown culminating in the end of the war by the end of 2011.  Paul's contention however, is based on his belief that the Constitution exclusively grants Congress power to both declare and terminate war. 

Paul's amendment on Tuesday night immediately drew fire from Sens. Carl LevinCarl Milton LevinHow House Republicans scrambled the Russia probe Congress dangerously wields its oversight power in Russia probe The Hill's Morning Report — Sponsored by CVS Health — Trump’s love-hate relationship with the Senate MORE (D-Mich.) and John McCainJohn Sidney McCainMulvaney aims to cement CFPB legacy by ensuring successor's confirmation Trump mocks McCain at Nevada rally Don’t disrespect McCain by torpedoing his clean National Defense Authorization Act MORE (R-Ariz.) who lead the Senate Armed Services Committee. Both warned that removing the authorization for the use of military force against Iraq could endanger embassy personnel and the few troops Obama plans to leave behind even after the war is officially over. 

Sen. Lindsey GrahamLindsey Olin GrahamSenate panel advances three spending bills Trump says he will sign executive order to end family separations Trump backs narrow bill halting family separations: official MORE (R-S.C.), who also serves on the Armed Services Committee, also argued that removing the authorization could endanger troops and embassy personnel and said there were was no gain to adopting the amendment. 

"I don’t know what you get from this amendment... I just don’t see the upside for those who are doing the fighting and who have to deal with these complications of this long protracted war," said Graham.

This is not the first time Paul has sought to strip the administration of war powers. Earlier in the year Paul became a vocal opponent of the administration's unilateral decision to participate in the NATO assault on the regime of Libya's former dictator Moammar Gadhafi.

"On several occasions this year, Congress has been ignored or remained silent while the president committed our forces to combat," Paul said in a statement also released in early November. "It is my intention to urge Congress to reclaim its constitutional authority over the decision to go to war, or to end a war — it is one of the body's most important powers."

The amendment was proposed to the Defense Department's authorization bill, which provides funding for fiscal year 2012.