"Syria is now saying they will give up their chemical weapons if, now this is the big 'if,' if Miley Cyrus gives up whatever it is she's doing," Letterman said.
Letterman then said Assad became a dictator of Syria against his own will because he felt obligated to follow his family's history of dictatorship.
"He originally did not want to go into the dictator business, he was studying to be an ophthalmologist," Letterman said. "In a related story, George W. Bush did not want to president, he was studying to be a dunk tank clown."
In the clip, Rose asked Assad if he considered chemical warfare equivalent to nuclear warfare.
"I don't know, I haven't tried either," Assad said smiling as Letterman's crew piped in fake laughter.