A Russian attack on a NATO ally would not necessarily lead to "all-out war", the UK's Defence Secretary said this morning.
Speaking at the Tory Party Conference, Ben Wallace said it is a "possibility" that Vladimir Putin could launch an assault on Poland - but he said it was unlikely.
If it did happen, NATO members including the UK would be treaty-bound to respond, but Mr Wallace said this would not necessarily mean a full blown conflict with Putin's forces.
The minister told a fringe meeting that the government is "deliberately ambiguous" about scenarios, but added: "Article 5 is very clear, an attack on one is an attack on all, that is solid and in concrete and will be stood by.
"Article 5 doesn't necessarily mean all-out war, people sometimes think it means the whole thing, but nevertheless there would be a response to an attack on NATO."
But he suggested an assault on Poland would be unlikely, stating: "There's a possibility, but a very small possibility. Poland is very far from where the battle is."
Mr Wallace said Ukraine is "absolutely vast", saying after his last visit to capital Kiev last week: "I wouldn't have known there was a war on all the way to Kiev, it's huge."
But in a bleak outlook he said he can't see "any light at the end of the tunnel" in Russia's brutal assault of Ukraine - and said it is for Russians, not the West, to overthrow Putin.
Mr Wallace said that the Russian President has continued to reject pathways to peace that could end the carnage, which has claimed thousands of lives.
He said an attack on Poland is "a possibility" and would draw a response from NATO members including the UK - but said this would not necessarily mean "all-out war".
Meanwhile the Cabinet member - who was an early favourite to become PM after Boris Johnson was ousted in July - said he doesn't regret not standing for the top office, saying: "The reality was it wasn't for me."
Former soldier Mr Wallace, who has been in post since August 2019, told a Conservative Home gathering he is pessimistic about the war ending swiftly, adding it will take time for Russians to fully grasp the devastation.
He said regime change is not on the western agenda, with Putin's leadership a matter for the Russian people.
Mr Wallace said: "The scale of death is coming back to the Russians, it will eventually take its toll but I don't see any light at the end of the tunnel."
He maintained that toppling Putin isn't a focus of the UK government or any other Western powers.
Mr Wallace stated: "We're not in the business of regime change, no one is. It's for the Russian people to decide their government and they have to do whatever they wish."
He said he believes Putin will continue to reject routes to peace - which he refers to as "off-ramps" - stating: "Every time we think there's a possibility for Putin to take an offramp he does the opposite, he builds a cage around himself."
The Defence Secretary continued: "I think even if you build him a gold off-ramp, he'd deliberately crash into it... I think we can see this ending with Russia continuing to do what he does in the hope that its brutality will be the battle-winning component, that's why it's so important that we don't let him win."
Following Mr Johnson's resignation, the Defence Minister - who can draw support from across the party - was the favourite to succeed him.
But he swiftly ruled himself out of the race, and said he had no regrets.
"If you want to be Prime Minister you have to really, really want it to the extent that nothing else matters," he said. "I didn't want it that much, I love the job I do, and if you pick the right winner you hopefully stay in your job.
"I want to finish what I started."
