Speaking at CNN's undercard Republican presidential debate in Las Vegas, Graham said that if the U.S. had left 10,000 troops on the ground, it would have prevented the rise of the Islamic State in Iraq and Syria (ISIS).
“The key is to not leave,” Graham said. “If we left Germany and Japan [after the first two world wars], God knows what would happen. Be patient. 
"If we had 10,000 troops left in Iraq, there would be no [ISIS]. And I hate what Obama did, he gave away everything we fought for and I hate what he did! I begged him not to.”
Graham has called for more ground troops in Iraq and Syria, but on Tuesday night declined to say whether he’d send additional U.S. military support to Libya to combat the rise of ISIS in that country.