Britain should not be "squeamish" about an alliance with Syrian President Bashar Assad to defeat the radical jihadists of Islamic State (IS), former known as ISIS, according to both a former defence secretary and the ex-head of the armed forces.
But Foreign Secretary Philip Hammond has ruled out allying with Assad, saying it would not be "practical, sensible or helpful". Hammond told BBC Radio 4's World at One: "No. We may very well find that we are fighting, on some occasions, the same people that he is but that doesn't make us his ally."
Former army chief Lord Dannatt suggested the West had got its priorities drastically wrong in Syria, and said it should return to an alliance with Assad, giving up any demands that he relinquish power.
"The old saying my 'enemy's enemy is my friend' has begun to have some resonance with our relationship with Iran," he said. "I think it's going to have to have some resonance with our relationship with Assad."
Speaking on the BBC Radio 4 Today programme, the peer said IS had to be "opposed, confronted and defeated" in both Iraq and Syria. "The Syrian dimension has got to be addressed. You cannot deal with half a problem," he said.
Lord Dannatt added: "I think whether it is above the counter or below the counter, a conversation has got to be held with him. Because if there are going to be any question of air strikes over Syria airspace it's got to be with the Assad regime's approval."
The former chief of the general staff said it was "worth just reflecting... who actually understood that country, Syria, best - was it us, was it other people, or was it Assad himself? It's clearly turned out over the last two or three years to be a very diverse, very complicated country," he said.
"I think the reason why, quite rightly, the British Parliament voted against intervention (in Syria) a year ago and we didn't join American air strikes was we couldn't be sure who we would be supporting. What's become quite clear overt the last couple of months is that IS are awful. They received a bloody nose from Assad themselves, that is why they have gone off to Iraq and are operating in Iraq."
His comments echo those of former defence secretary and chairman of parliament’s intelligence and security committee Sir Malcolm Rifkind.
“[IS] need to be eliminated and we should not be squeamish about how we do it,” he told the Financial Times. “Sometimes you have to develop relationships with people who are extremely nasty in order to get rid of people who are even nastier.
“We have to deal with facts on the ground, not as we would want them to be but as they are,” he continued, comparing the potential alliance to the way the Allies worked with Josef Stalin during World War Two. “The idea that we can have a military operation in Iraq that won’t have a Syrian dimension is inconceivable.”
Lord Dannatt said he believed more UK special forces may need to be deployed on the ground in Iraq to train Kurdish troops how to use weapons. He also suggested the "time will come" when the Government decides that British planes should carry out air strikes, rather than leaving it to the US.
The peer repeated his call for Parliament to be recalled to discuss the crisis, adding that it should be in the next fortnight. Lord Dannatt appeared to have forgotten Parliament returns on September 1 in any event.
The calls have so far fallen on deaf ears, at least in Washington. Ben Rhodes, President Barack Obama’s deputy national security adviser, said on Wednesday that Assad was “part of the problem”.
The frostiness in relations between the West and the Assad regime dates back only to 2011, and the popular uprising against the leader by more moderate groups. It had been hoped by both Europe and America that Assad would prove to be both a moderate and a moderniser.
Assad visited then-Prime Minister Tony Blair in Downing Street in 2002, spoke to both the Queen and Prince Charles, and the Labour prime minister considered asking the Queen to bestow an honorary knighthood on the President, the Times revealed in 2012.
Assad was given a banquet in his honour at Mansion House, hosted by the lord mayor of London, and his wife Asma hosted a tea party with Cherie Blair.
Blair's US-counterpart at the time, President George W Bush, has since declared he was "not a fan" of Assad. His father, George Bush Snr, had had cordial relations with Bashar Assad' father Hafez Assad during the Gulf War, and helped negotiate the release of hostages held in Lebanon.
The Syrian government did have some limited intelligence co-operation with the allies fighting the so-called "War on Terror" but opposed the US incursion into Iraq. The gentle warming of ties continued initially with US President Barack Obama, who appointed an ambassador to the country in 2010, the first in five years, and initially resisted condemning the harsh crackdown on pro-democracy protesters by the Assad regime in 2011, which then Secretary of State Hillary Clinton calling Assad a "reformer".
As the violence against protesters worsened and civil war broke out in parts of the country by August that year, Obama called for Assad to stand down. By October, ambassador Robert Ford was receiving daily threats and had his car attacked by mobs, and he was withdrawn from the country. The US order the Syrian charge d'affairs in Washington to leave the country in May 2012, after the Houla massacre committed by pro-regime Shabiha killed 108 people, including 49 children.
The UK foreign office has closed its embassy in Damascus, and all diplomatic personnel have been withdrawn since the civil war escalated, with the Cameron government making repeated calls for Assad to stand down.