Alexander Vindman: "We are about to start the biggest war in Europe since the Second World War."

Alexander Vindman, a Ukrainian immigrant best known for his award-winning role as a star witness in Trump's first impeachment trial, said Wednesday on NBC's "Morning Joe" program that it's probably too late to avoid a war with Russia in Ukraine.

"These things are already in motion," he said. "It's almost certain to happen, and now is the time to take these last-minute steps."

"Now is the time" to send weapons to Ukraine, Windman said. "What we are doing now is less escalatory than the options that we will have to implement in mid-February, after this unfolds."

Windman serves in the US Army with the rank of colonel, although Ukraine has offered him the post of Defense Minister.