One of Britain’s most senior intelligence chiefs has questioned whether the US could be trusted to protect European states if they were attacked by Russia.

Sir John Sawers, a former head of MI6—also known as “C”—said central European states should “question” whether the US would enact Article 5 of the NATO Treaty in the event of an attack by Russia.

Article 5 of the treaty states that if a member country is attacked, all other members will come to its defence.

Sir John, who served as “C” from 2009 to 2014, also said that the humiliation of President Volodymyr Zelenskyy by President Donald Trump and Vice-President JD Vance was clearly a “set-up” and a “disgrace”.

In an interview with the BBC Today programme, he added: “There’s no doubt that the last week has seen a setback for Ukraine’s interests. Ukraine is in a weaker position now because of the row in the White House.”

The row was a “set-up”, he added. “The Vice-President does not speak in those sorts of settings unless it was pre-planned by Trump that Vance should come in and goad Zelenskyy in the way that he did, and Zelenskyy unwisely rose to the bait.

“It was a disgrace that the Americans set that up in the way they did, but this is a different sort of administration, and they operate in a different sort of way. We do have to recognise that they are the most powerful country in the world, and we all have to work with them.”

Referring to Article 5 of the NATO Treaty, he said: “If I were a small European country in the centre of the continent, I would have a big question mark in my mind as to whether NATO’s Article 5 guarantee could be relied upon under this presidency.

“We have to preserve what we can of the transatlantic relationship over what will be a very turbulent four years. That NATO security guarantee was always sufficiently credible that Soviet and Russian leaders always avoided a confrontation with NATO.”

He also warned that Russia was likely to continue attacking Western infrastructure and said it was possible that the Kremlin might launch a military incursion into Poland or the Baltic states.

He added: “I think we might see not just Putin continuing conflict in Ukraine, but he will also continue to attack Western infrastructure, and we may see some incursions across the border into the Baltic states just to test Article 5 and see how NATO responds. So, we do have to gird ourselves for a very difficult security environment in Europe. The Russians will also go back to their earlier demands for NATO forces to be pulled out of Poland and the Baltic states back to their pre-1997 deployment positions. So, at the moment, the initiative is with the Russians, unfortunately, and we have to gird ourselves for dealing with that over the coming months and years.”

Sir John disputed President Trump’s claim that the US had supplied more military equipment to Ukraine than Europe, adding: “The bulk of the support for Ukraine—about 60 per cent—has come from Europe and less than 40 per cent from the US. But it is the Americans who have been providing the high-end military kit, which will be very hard for the Europeans to substitute.”

Meanwhile, UK Prime Minister Keir Starmer has announced a four-point plan to work with Ukraine to end the war and defend the country from Russia.

The UK, France, and other countries will step up their efforts in a “coalition of the willing” and seek to involve the US in their support for Ukraine, he said on Sunday—after calling a summit of 18 leaders, mostly from Europe and including Volodymyr Zelenskyy, three days earlier.

“We are at a crossroads in history today,” Starmer said after the summit, while Zelenskyy said Kyiv felt “strong support” and that the gathering showed “European unity at an extremely high level not seen for a long time.”

“We are all working together in Europe in order to find a basis for cooperation with America for a true peace and guaranteed security,” Zelenskyy said after the summit.

French President Emmanuel Macron told Le Figaro newspaper that Paris and London wanted to propose a one-month truce between Russia and Ukraine “in the air, at sea, and on energy infrastructure”.

Speaking at a news conference shortly after the meeting of leaders, Starmer said four points had been agreed: to keep military aid flowing into Ukraine and to keep increasing the economic pressure on Russia; that any lasting peace must ensure Ukraine’s sovereignty and security, and Ukraine must be present at any peace talks; in the event of a peace deal, to boost Ukraine’s defensive capabilities to deter any future invasion; and to develop a “coalition of the willing” to defend a deal in Ukraine and to guarantee peace afterwards.

Starmer also announced an additional £1.6bn ($2bn) of UK export finance to buy more than 5,000 air defence missiles. This comes on top of a £2.2bn loan to provide more military aid to Ukraine, backed by profits from frozen Russian assets.