Britain is resigned to Syrian President Bashar al Assad remaining in power and Russia gaining a new sphere of influence in the region, the foreign secretary has signalled.
But Jeremy Hunt cautioned that Moscow has also taken on responsibility for securing peace in the country because of its support for the regime.
It is the first time a British minister has spoken so frankly about the reality in Syria as Assad forces consolidate their grip on power after regaining towns and cities seized in a rebel uprising – supported by the UK and its allies – that began in 2011.
In a wide-ranging interview with Sky News the foreign secretary also:
:: Praised Donald Trump as a unique president who should not be underestimated even as he disagreed with him over plans to pull troops out of Syria and Afghanistan
:: Said Islamic State (IS) is not defeated by “a long way”
:: Revealed the fate of two suspected IS militants from the UK who are being held by Syrian Kurdish forces must be decided this year
The foreign secretary’s strongest remarks were in recognition of Assad’s consolidation of power in Syria with support from Russia and Iran.
“I think you know the British longstanding position is that we won’t have lasting peace in Syria with that regime,” Mr Hunt said, speaking in Singapore during a three-day trip to Asia.
“But regretfully we do think he’s going to be around for a while and that is because of the support that he’s had from Russia.”
The foreign secretary continued: “Russia may think that it’s gained a sphere of influence. What we would say to them is yes and you’ve also gained a responsibility.
“If you’re going to be involved in Syria then you need to make sure that there really is peace in Syria. And that means making sure that President Assad does not use chemical weapons on his own people.”
Former chief of the defence staff General Lord David Richards said he “reluctantly” endorsed Mr Hunt’s position.
He told Sky News: “I’m no apologist for Russia or the Assad regime but actually this has been staring us in the face for a number of years now, and I think it’s time to turn a page and accept reality. Our strategy – if that is the right word – failed miserably and Russia’s with Iran has been successful.
“We did offer a coherent military strategy – a military strategy has to be a synthesis of military actions with political actions – and that of course was why Russia’s has been successful whereas ours has not been.”
Mr Hunt’s comments mark a shift from his predecessor Boris Johnson, who said a year ago that Assad should be allowed to run for re-election as part of a peace settlement.
Britain had previously demanded Assad stand down, saying he has no legitimacy to rule after launching deadly attacks, including with chemical weapons, against his own people.
Some countries that had supported the uprising against the dictator are now seeking to mend ties with the regime. The United Arab Emirates reopened its embassy in Damascus last month and Bahrain is following suit.
Mr Hunt did not appear surprised about Assad’s renewed popularity.
“He’s been able to consolidate his position. There will be many people in Syria who are bitterly disappointed but that has been the outcome,” he said.
“But if that is the outcome then they’re going to be countries that want to re-establish diplomatic ties.”
There is also growing speculation that the Arab League could invite Syria back into its fold after expelling the regime in 2011 over its brutal crackdown on the resistance.
Turning to the other main dimension of the Syria conflict – the US-led fight against Islamic State – Mr Hunt said he agreed with a decision by President Trump to slow a planned pull-out of some 2,200 US forces from the country.
But he cautioned against a full withdrawal.
“Daesh (IS) is far from defeated and although they’ve lost most of the land that they hold, which is a very positive thing, they are still a force,” he said.
“What we don’t want to do is inadvertently create a situation where they are able to regather their strength… It’s very important we don’t declare victory before we really know that we’ve secured it.”
Mr Trump had taken allies by surprise last month by initially announcing a rapid exit plan and declaring victory over IS in Syria.
Another dilemma for Britain is what to do with two members of a four-strong IS torture and murder squad dubbed the Beatles.
Alexanda Kotey and El Shafee Elsheikh have been stripped of their British citizenship and are being held by Syrian Kurdish forces. But concern has been raised that all IS detainees could be set free once US troops – allied with the Kurds – leave Syria.
“That is one of the issues that is going to have to be resolved during the course of this year,” Mr Hunt said.
He did not rule out the possibility that the pair could be brought back to the UK to stand trial – an idea that Gavin Williamson the defence secretary has repeatedly rejected.
“I wouldn’t want to speculate on what the solution would be,” Mr Hunt said.
“But I would simply say that our priority in this has always been one very simple priority just make sure these evil men see justice.”
Away from Syria, the foreign secretary indicated Britain was not about to cut its troop numbers in Afghanistan despite talk that President Trump was seeking to halve his.