Tucker Carlson had a heated exchange with defense policy expert Max Boot, who advised former Massachusetts Gov. Mitt Romney's 2012 presidential campaign.
Carlson debated Boot on the merits of an argument made by Fox News military analyst Col. Ralph Peters, who likened Carlson's stance on Russia to Charles Lindbergh's stance on Nazi Germany.
Peters later retracted the comparison, but maintained his viewpoint on Russia.
"Mitt Romney was right when he said that Putin is the largest geopolitical threat," Boot said.
Boot criticized Carlson for "yukking it up with Mark Steyn" about the prospect of Russian collusion in an American election.
Carlson said Boot had a problem with humor and that he too often dismisses people as "immoral."
He added that Boot was "consistently wrong" in his foreign policy prognostications.
Boot has supported toppling malevolent regimes like that of Muammar Qaddafi, Saddam Hussein and Bashar Assad.
Carlson said Boot's predictions about Qaddafi and Hussein were wrong and that he should "choose another profession... like housepainting."
"You specialize in moral outrage," Carlson said.
Watch the entire heated exchange above.