Graham: Americans fighting with ISIS are enemy combatants

Sen. Lindsey Graham (R-S.C.) said Wednesday all U.S. citizens who join Islamist militant organizations in the Middle East should be defined as enemy combatants and subject to capture or death. 

Graham said he is preparing a letter asking President Obama if he agrees with that categorization of U.S. citizens who join the Islamic State in Iraq and Syria (ISIS).

"All of these American citizens who are going to jihad for ISIS or any other organization should be considered as enemy combatants under the American law of war, subject to being killed or captured," he said on Fox News' "On the Record with Greta Van Susteren."

At least 140 U.S. fighters have traveled to Syria or Iraq to fight, according to intelligence officials cited in an NPR report Wednesday. One U.S. fighter linked with ISIS was confirmed dead over the weekend, with reports of a second

"I don't know if it's 140. One is too many," Graham said. "But if this war continues and ISIS continues to win and is seen as a conquering jihadist hero in the eyes of these disturbed people throughout the world, there's going to be 1,400."

The South Carolina senator said Obama has been "derelict in his duties" to get ahead of the threat posed by Western fighters in Syria. Officials and lawmakers have warned about the potential for a Western fighter to reenter the United States and carry out a domestic attack. 

Graham said the threat emerged because of Obama's inaction, citing the president’s decision to seek approval from Congress last year to use military action to degrade Syria's chemical weapons. 

Syria eventually agreed to destroy the weapons, and no military operation was approved. 

"I don't have any confidence at all that he understands the threat to our country," Graham said of Obama. "And his indecision upon indecision is putting our homeland at risk."