WATCH: Conservative CNN commentator spars with 'Russia apologist' scholar over Trump-Putin summit

During a heated panel discussion on CNN, a Moscow-born conservative commentator accused a Russian studies scholar of being an "apologist" for Vladimir Putin.

Stephen Cohen, professor emeritus of Russian studies at NYU and Princeton, told CNN's Anderson Cooper that he doesn't find anything "unusual" about President Donald Trump and Putin's private meeting in Helsinki earlier in the month. He went on to claim that he believes Putin's assertion that he and his American counterpart discussed a resolution to Russia's annexation of Crimea.

"You have to take Putin's word this is what they talked about," Cohen said. "I don't want to shock you, but I believe Vladimir Putin on several things."

Max Boot, a Russian-American conservative commentator and fellow at the Council on Foreign Relations, noted that "a lot of intelligence officials think that there is something highly suspect in the relationship between Putin and Trump" based on the president's apparent unwillingness to criticize the Russian leader the way he does others. 

"I have no idea what Mr. Boot is talking about," Cohen argued. "He wants Trump to threaten Russia? Why would we threaten Russia?"

The Russian studies scholar attempted to continue his line of reasoning, but Boot cut him off.

"Because they're attacking us, Professor Cohen. Russia is attacking us right now according to Trump's own director of national intelligence," he said. 

"I've been studying Russia for 45 years," the professor retorted. "I've lived in Russia, and I've lived here."

Boot cut him off once again, saying Cohen has been "consistently an apologist for Russia those 45 years."

At the word "apologist," the professor paused before asking Boot what he called him. The conservative commentator repeated himself — and Cohen launched into a diatribe.

"I don't do defamation of people, I do serious analysis of serious national security problems," the professor said. "When people like you call people like me, and not only me, but people more eminent than me, apologists for Russia because we don't agree with your analysis, you are criminalizing diplomacy and detente and you are the threat to American national security, end of story."

"Why do you have to defame somebody you don't agree with?" Cohen continued. "They used to do that in the old Soviet Union."

Boot merely laughed as Cooper moved on to the next topic.

Watch below, via CNN: