Senators: Iran fight could make ISIS debate more difficult

Senators on Tuesday said acrimony between Republicans and Democrats over Iran made reaching an authorization for military force against the Islamic State in Iraq and Syria (ISIS) a little more difficult. 

Forty-seven Senate Republicans sent an open letter to directly to Iran this week, warning that any deal negotiated to rollback its nuclear program might not last beyond President Obama, outraging Democrats and the White House. 

However, reaching an authorization for the use of military force (AUMF) will take bipartisanship, and both sides already disagree on how it should be worded, noted Sen. Jeff FlakeJeffrey (Jeff) Lane FlakeTrump defends border deployment amid fresh scrutiny Sunday shows preview: New members preview agendas after Democratic House takeover Veteran political reporter says New Hampshire voters have 'hunger' to moderate political turbulence MORE (R-Ariz.). 

"It's a difficult environment. There's a lot of animosity, obviously, and that has manifested in a lot of these issues, but these are too important to let divide us," he added.

But he added, "I think we can get there, I hope we do. Our allies and our enemies need to know that we speak with one voice."

Sen. Bill NelsonClarence (Bill) William NelsonDems seek to overhaul voting rules in Florida legal fight  Election Countdown: Abrams ends fight in Georgia governor's race | Latest on Florida recount | Booker, Harris head to campaign in Mississippi Senate runoff | Why the tax law failed to save the GOP majority Trump's take on midterms: ‘Epic' win in Senate, ‘better than other sitting Presidents’ in House MORE (D-Fla.) was less sanguine.

"When 47 Republican senators try to cut the legs out from under the president and negotiations that are proceeding now in Geneva -- I was flabbergasted and if that can happen in these days, then I can't predict anything with the AUMF," he said.

Nelson said he was "absolutely appalled and saddened by" partisanship being injected into foreign policy and national security.

"What it sends is a message  to the rest of the world is that we are not united when these kinds of letters are being written," he said. 

The Senate Foreign Relations Committee is scheduled to question Secretary of Defense Ash Carter, Secretary of State John KerryJohn Forbes KerryTrump set to have close ally Graham in powerful chairmanship Kerry: ‘People are going to die' due to Trump's withdrawal from Paris climate deal Kerry tears into Trump for skipping visit to military cemetery: ‘Truculent child president’ MORE, and Chairman of the Joint Chiefs of Staff Gen. Martin Dempsey on Wednesday morning as part of its efforts to craft an AUMF. 

Sen. Susan CollinsSusan Margaret CollinsMcConnell, Flake clash over protecting Mueller probe Overnight Defense — Presented by Raytheon — Border deployment 'peaked' at 5,800 troops | Trump sanctions 17 Saudis over Khashoggi killing | Senators offer bill to press Trump on Saudis | Paul effort to block Bahrain arms sale fails Senators introduce bill to respond to Khashoggi killing MORE (R-Maine) said it's difficult to predict whether there would be an AUMF reached. 

"It has not resonated very well with people on either side of the aisle for totally different reasons so I'm not sure what the outcomes could be," she said.