Boris Johnson has insisted that Vladimir Putin is not “mad or ill” and will not use nuclear weapons in his war against Ukraine.
The former prime minister said the Russian president had made a “historic miscalculation” with his invasion.
He also piled further pressure on Western leaders to provide more help to Ukraine in an interview in the United States with the Atlantic Council think-tank.
Johnson said: “What is the point of having Challenger tanks patrolling the beautiful villages of Wiltshire - which is a very safe area I can tell you - when the Ukrainians could be using them now to bring this war to an end?
“Every time we’ve been asked to intensify our support, we’ve be met with the same argument that we risk an escalation by Putin.
“How can we seriously worry about provoking him when we have seen what he will do without the slightest provocation?
“He isn’t mad. He isn’t ill. He simply made a historic miscalculation and is struggling to deal with the position in which he has now placed his own country.
“He won’t use nuclear weapons because they would instantly extinguish the last flicker of Chinese support.
“It would lose him every one of the world’s swing voters from India to Africa to Latin America.
“He would terrify his own people if he did so who would live in dread of the consequences for them.
“He would plunge Russia into such a cryogenic freeze of economic isolation as to make the present sanctions regime seem like a blessing.”
Johnson said western leaders must not fall for Putin’s “trick” that the war is a stand off between a nuclear armed Nato and nuclear armed Russia.
Johnson has recently made a series of interventions in media interviews while his allies continue to urge him to make a comeback.
Only this week he condemned prime minister Rishi Sunak’s decision not to send British fighter jets to Ukraine.
He also made an extraordinary claim that Brexit “helped save lives” during the Covid-19 pandemic.