Fresh off his war of words with Secretary of State Hillary Clinton, Russia's once-and-future President Vladimir Putin is calling out another senior U.S. politician: Sen. John McCain (R-AZ).

Unlike Clinton, who doesn't actually want to be trading insults with Putin in the press, McCain relishes these types of confrontations. In fact, McCain might have even started it when he tweeted on Dec. 6, "Dear Vlad, The ArabSpring is coming to a neighborhood near you."

That was a reference to the anti-Putin rallies in Moscow to protest Russia's parliamentary elections, which Clinton called "not free and fair."

On Thursday, Putin insulted McCain during a TV call-in show.

"He has the blood of peaceful civilians on his hands, and he can't live without the kind of disgusting, repulsive scenes like the killing of Qaddafi," Putin said.

Putin then took his insults one step further, accusing McCain of losing his marbles when he was a prisoner of war in Vietnam.

"Mr. McCain was captured and they kept him not just in prison, but in a pit for several years," said Putin. "Anyone [in his place] would go nuts."

McCain responded Thursday morning on Twitter, writing, "Dear Vlad, is it something I said?"

Putin didn't even address McCain's comments at the Foreign Policy Initiative Forum on Tuesday in Washington, when he accused the entire Russian government of corruption.

"I think this a corrupt system -- an oligarchy.... This is a kleptocracy.  It's certainly not a representative government," McCain told the forum.