A Reuters/Ipsos online poll this month asked 2,809 Americans to rate how much of a threat a list of countries, organizations and individuals posed to the United States on a scale of 1 to 5, with one being no threat and 5 being an imminent threat.

The poll showed 34 percent of Republicans ranked Obama as an imminent threat, ahead of Putin (25 percent), who has been accused of aggression in the Ukraine, and Assad (23 percent). Western governments have alleged that Assad used chlorine gas and barrel bombs on his own citizens. View the graphic.

Given the level of polarization in American politics the results are not that surprising, said Barry Glassner, a sociologist and author of "The Culture of Fear: Why Americans are afraid of the wrong things."

"There tends to be a lot of demonizing of the person who is in the office," Glassner said, adding that "fear mongering" by the Republican and Democratic parties would be a mainstay of the U.S. 2016 presidential campaign.