President Obama's decision to withdraw all troops from Iraq by Christmas could very well come back to "haunt" the U.S., Sen. Lindsey GrahamLindsey Olin GrahamAlabama election has GOP racing against the clock Graham on Moore: 'We are about to give away a seat' key to Trump's agenda Tax plans show Congress putting donors over voters MORE (R-S.C.) said.

"I respectfully disagree with President Obama. I feel all we have worked for, fought for, and sacrificed for is very much in jeopardy by today’s announcement," Graham said Friday in a statement. "I hope I am wrong and the President is right, but I fear this decision has set in motion events that will come back to haunt our country."

Graham's statement came a few hours after President Obama announced that the Iraq war was over and that all U.S. troops in Iraq would be withdrawn by the end of the year.

"Today I can say our troops in Iraq will definitely be home for the holidays," Obama said at the press conference where he made the announcement.

The White House had previously planned on leaving between 3,000 and 5,000 troops in Iraq past the end of 2011. Those plans changed after the Iraq government decided not to give the remaining U.S. soldiers immunity from prosecution in Iraqi court.