Mr Corbyn has been accused of weakening Europe’s defence after saying he would not defend invaded allies.
Ex-NATO Secretary General Anders Fogh Rasmussen has argued that Putin will have free reign to launch attacks with Mr Corbyn in No.10 and loudmouth Donald Trump in the White House.
He added the potential line-up would also “weaken the whole of Western civilisation”.
NATO’s “collective defence” principle says an attack on one is an attack on all, and Mr Rasmussen claimed Mr Corbyn’s inaction leaves Europe weakened.
Mr Corbyn refusal to uphold NATO’s principle has “undermined” the credibility of it’s defence, Mr Rasmussen told BBC’s news night.
He said: “I think his refusal to clearly state that as a possible prime minster of the UK, he would not be sure that he would defend NATO allies has really, really undermined the credibility of NATO.
“And if he were to carry out what he has said it would tempt Mr Putin to aggression to test the resolve of NATO.”
He added that it is unlikely that the Russian president would launch an open attack on the West, but that he might engage in a sinister “hybrid warfare”.
Mr Rasmussen warned that tactics seen in the annexation of the Crimea might become much more common if Mr Corbyn was in charge.
Mr Corbyn’s message “that NATO should give up and go home, go away” were almost exactly the same words uttered by Putin, Mr Rasmussen said.
The security chief warned that parallels between Mr Corbyn and Mr Putin would mean the Kremlin would be very happy to see the Labour leader in power.
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He said: “So there is no doubt that if Mr Corbyn were to be elected prime minster of the UK there will be a big, big celebration in the Kremlin.

He added Mr Crobyn was at odds with his party and that he had “betrayed the fundamental principles upon which the Labour Party usually worked in the past.”
It comes after an embarrassing situation where Corbyn supporters used the hashtag #StayPutInLabour, which suggested Putin was for the Labour leader.

By Alex Hickson