Vladimir Putin clearly is "unsettled" by the protests in his country, Sen. John McCain told Fox News on Thursday, after the Russian leader publicly excoriated the Arizona Republican in a personal attack the U.S. senator described as just "strange." 

The bout of transnational name-calling started after the Arizona senator and former Republican presidential nominee took to Twitter with a few words of warning to Putin. 

"Dear Vlad, The #ArabSpring is coming to a neighborhood near you," McCain tweeted. 

Putin, in a TV appearance Thursday in Russia, then accused McCain -- a Vietnam War veteran and former prisoner of war who now is ranking Republican of the Senate Armed Services Committee -- of having "a lot of blood of peaceful civilians on his hands." 

According to the account in The Associated Press, Putin said that because McCain was kept "in a pit for several years" in Vietnam, "anyone would go nuts." 

McCain, in an interview with Fox News, said it appears Putin is "a little bit stunned" by what's happening in his country. 

"It's very clear that these uprisings and demonstrations in Russia have really unsettled him and the oligarchy that controls Russia," McCain said, describing Russia's leadership as a "kleptocracy." 

"I think that's pretty clear why he reacted in such a strange and vociferous fashion," McCain said. 

Russia has been the scene of historic protests following its parliamentary elections earlier this month --- the elections precede another round of voting in March which Putin, now prime minister, hopes will return him to the presidency. Putin has denied fraud allegations and accused demonstrators of trying to disrupt the country. 

Putin personally went after McCain in his remarks, even criticizing him for the death of ousted Libyan leader Muammar Qaddafi

"He must relish and can't live without the disgusting, repulsive scenes of the killing of Qaddafi," Putin reportedly said. 

After the remarks were published, McCain again tweaked Putin on Twitter. 

"Dear Vlad, is it something I said?" he wrote.