Former Fed Chairman Alan Greenspan told CNBC on Friday he's pessimistic about the Ukraine crisis because it appears that Russian President Vladimir Putin is trying to put the Soviet Union back together.
"Putin probably, almost certainly, thinks that one of the great disasters of the 20th century was the demise of the Soviet Union," Greenspan said in a "Squawk Box" interview. "It's very obvious that he's trying to work its way back and maintain something similar to that sort of institution."
He added, "I don't see that we have the capability of preventing it—except, if we can affect their financial system significantly that it creates deterioration within Russia."
"Diplomacy is really far less important than the stock movements within Russia," Greenspan said, because in past confrontations there really wasn't much of a stock market in Moscow.