Donald Trump has “emboldened” Vladimir Putin and other dictators around the world with plan to end the Ukraine war, according to a former defence secretary.
Ben Wallace said the US has given up its position as a “moral leader defending freedom” around the world.
He also warned that Putin “will rearm and be back” for the rest of Ukraine unless Europe does more to back the government in Kyiv.
Trump held a 90-minute phone call with the Russian president yesterday before announcing that negotiations would “immediately” begin to end the war, which began nearly three years ago.
Earlier, new US defence secretary Pete Hegseth said it was “unrealistic” to expect Ukraine’s borders to go back to where they were before 2014, when Russia annexed Crimea.
He also said that the prospect of Ukrainian membership of Nato would be off the table in any peace deal.
On Times Radio on Thursday, Wallace said: “The world has been better when the United States was both a moral leader, defending freedom, democracy and a military leader.
“And that language is a reversal of that. And that is something that we should all really worry about in the short term.”
The former Tory MP added: “Make no mistake, make America great again, America first, put everything first for Donald Trump.
“And that means we’re going to have to both step up to fill the void in Europe and show our own leadership. And, you know, there’s no harm in doing that. We could do that today if we wanted to.
“But it is also a signal that I’m afraid will embolden the likes of the Putins, the President Xi’s, the Iranians, because they will now see that what preoccupies the United States is purely really a domestic agenda and its own shores.
“And it will be ambiguous at best when it comes to protecting sovereignty, freedom and democracy. And I think that’s the biggest worry we have to face.”
America has also signalled that it will play no part in policing any peace deal to make sure it holds, meaning European nations like the UK will need to provide troops to make sure Russia does not attack its neighbour again.
Wallace said: “The big question is, do we want to put our money where our mouth is? Do we want to actually turn our rhetoric into action?
“Now, the exact mechanism of how you would secure Ukraine from Putin coming back, because that is the big question for Zelenskyy. Last time he invaded in 2014, the West did nothing. Putin comes back for another bite of the country.
“I don’t trust Putin an inch. And without any form of mechanism or indeed guarantees, he’ll be back. He will rearm and he will be back. His stated aim is that Ukraine doesn’t really exist. He believes it’s part of greater Russia. So he will be back.
“And that’s the question Zelensky has to answer his people. How do we make sure that 2014, 2022 doesn’t become 2028? And we need that as a solution.”
Meanwhile, Downing Street has insisted that there is no divergence between the UK and the US when it comes to Ukraine.
Keir Starmer’s spokesman said: “The prime minister supports president Trump’s desire to bring this barbaric war to an end. Russia could do this tomorrow if it withdrew its forces and ended its illegal occupation.”
He added: “As president Zelenskyy said, we share a desire to bring this war to an end. We’ll engage in those discussions with the US and Ukraine on exactly how we go about that, but the important thing is there can be no negotiation about Ukraine without Ukraine.
“We’re focused on putting Ukraine in the strongest possible position to ensure it is able to achieve a just and lasting peace.”