The brutal murder of one British aid worker and threat to kill a second will add urgency to efforts today to form a substantial international coalition to mount an assault on Islamic State (IS) extremists.
Foreign Secretary Philip Hammond will attend a summit in Paris as Washington seeks military commitments from more regional and global allies for the fight to push back the jihadist advance.
David Haines, whose beheading by an English-accented militant was shown in a video posted by IS on Saturday, was apparently killed by the same cell which took the lives of two American journalists in recent weeks.
Another British hostage – former cab driver Alan Henning, who was snatched after travelling to Syria as part of an aid convoy – was named in the video as the next in line to be killed.
Prime Minister David Cameron vowed to “hunt down” the “monsters” who murdered the man he dubbed a “British hero” and said the crime would “strengthen our resolve” to smash the extremist network which has seized swathes of Iraq and Syria.
But although Britain was ready to take “whatever steps are necessary” as part of an international mission against IS and continue arming Kurdish forces and providing humanitarian help, he gave no signal over whether he would commit military forces to air strikes.
US secretary of state John Kerry is pressuring allies – especially Middle East and Gulf states – to show a united front and Washington is confident of securing commitments to provide ground troops, a step ruled out by the UK.
Australia yesterday promised 10 military aircraft and 600 personnel – but not combat troops.
Downing Street was last week forced to insist it had not ruled out any options after Mr Hammond appeared to rule out joining air strikes on Syria.
London Mayor Boris Johnson said Britain would be “mad” not to deploy its military prowess to tackle IS.
“For all our occasional spasms of self-doubt, we are one of the great powers of the world with some of the finest armed forces. We would be mad not to use our defence capability, where we can, to make the world a better place,” he wrote in his Daily Telegraph column.
He also urged Sunni and Shia Muslim nations to set aside differences and unite to tackle IS – pinning the blame for the extremists’ rise on funding and encouragement provided by Saudi Arabia and others in a bid to counter the influence of Iran.
Mr Haines’s killing was angrily condemned across the UK, with the Archbishop of Canterbury joining political leaders and senior representatives of British Muslims speaking out to decry it as a “perversion” of the faith.
The 44-year-old father of two’s brother said radicalisation was the biggest threat to global safety but, in an emotional filmed statement, quoted verses from the Koran to highlight that it was a personal, not religious, issue.
Mike Haines,said harsh penalties should await Britons fleeing to Syria to join the fundamentalist group – which is also known as Isil.
“The Muslim faith is not to blame for Isil, nor is it the fault of people of Middle Eastern descent.
“The attraction of complete control and the use of terror as an implement of operational control has a widespread appeal to many disenfranchised throughout society, as you can see by the amount of foreign nationals, not just British.
“We need as a society to look at how we deal with this problem. My family and I agree with the Government that we need those travelling to fight for Isil and on their return to the UK to face the consequences of their actions.”
Attention has now also turned to the fate of Mr Henning, described in reports as a “very likeable” 47-year-old former cab driver from the Manchester area who had been so affected by a visit to a Syrian refugee camp that he felt compelled to return.
The Bolton News reported that Mr Henning and eight other volunteers travelled from the town to Syria in December.
Downing Street has ruled out any immediate recall of Parliament but former military chiefs are among those pressing for the UK to join air strikes.
Mr Cameron said the UK would seek to “mobilise the broadest possible support to bear down” on IS at the United Nations as efforts continue to form a coalition of countries – especially those in the region – to take part in a concerted offensive.
“This is not about British combat troops on the ground, it is about working with others to extinguish this terrorist threat. As this strategy intensifies we are ready to take whatever steps are necessary to deal with this threat and keep our country safe,” he said.
Scotland’s First Minister Alex Salmond criticised the lack of a clear wider international strategy to tackle the threat of IS and insisted any action should only be taken with the approval of the UN.