"You know, the RAND Corporation did a little war game on the table. They go, 'Oh, you can move here in 60 hours'," he said, referring to a war game scenario that saw Russian forces reach Tallinn and Rīga in 60 hours at most.
"You can't drive a tank to Rīga from the Russian border in sixty hours unopposed, let alone with people trying to stop you. There's swamps, there's forests, the roads are narrow," said the defense expert.
"The terrain here is the most defensible terrain anywhere in Europe," he said.
You can watch the full interview below (after a brief advertisement).
"To invade the Baltics they [the Russians] have to move forces to Belarus, which they have done in 'Zapad' exercises in 1999, 2013. Those exercises involved [preparing for] invading the Baltics and eastern Poland," he said.
"But those forces aren't there in peacetime. So if you're going to invade all the Baltics... you have to move these forces into Belarus," he said.
"If the NATO countries just sit and watch that happen and don't react, that's a large force that can overrun people fairly quickly. If the governments of the Baltics, Poland and NATO reciprocally respond to this Russian deployment... it's not an easy fight for the Russians," said Karber.
The interview also discusses the course of the military confrontation in eastern Ukraine and explains several war games played out by the Potomac Foundation, a think-tank headed by Karber.