"The impact of those words and those actions will play out for some time, a vivid reminder of the corrosive effect of Putin's war on his own society and his own regime," Burns said.

He called the war a "strategic failure" for Moscow that has exposed military weaknesses, hurt the economy and spurred a bigger and stronger NATO.

"Disaffection with the war will continue to gnaw away at the Russian leadership ... That disaffection creates a once-in-a-generation opportunity for us at CIA," he said.

"We're not letting it go to waste," he added, noting the CIA recently posted on Telegram to let Russians know how to reach the CIA via the dark web. 

"We had 2.5 million views in the first week, and we're very much open for business."