An interview that went off the rails on CBS’s “The Late Show with Stephen Colbert,” in which Colbert confronts filmmaker Oliver Stone about his apparently warm, fuzzy feelings toward Russian President Vladimir Putin, was just the tip of the iceberg, according to The New York Post’s Page Six.

You can watch the interview below, as it was posted by CBS. But The Post reports that the real fireworks, a clash about Israel, wound up on the cutting-room floor.

The publication quotes a source who was in the audience saying the political argument was “painful to watch.”

“The audience member explained that as Colbert pressed Oscar winner Stone — who was promoting his new Vladimir Putin Showtime series, ‘The Putin Interviews’ — on his apparent sympathy for the Russian president in spite of claims about Russian interference in the US election, Stone, at a disadvantage, tried to shift the talk to Israel,” The Post reports. “The source said they ‘watched from behind [their] hands’ as Stone said words to the effect of: ‘Israel had far more involvement in the US election than Russia.’”

The report adds: “The ‘Platoon’ director further challenged Colbert by saying, ‘Why don’t you ask me about that?’ — but we’re told that the host shot back, ‘I’ll ask you about that when you make a documentary about Israel!’”

Here’s a clip of the part that did make it to air …