A former defence chief has called the air strikes on Syria a “missed opportunity” to impact the civil war and said Britain should send soldiers in to protect people from the Bashar Al-Assad regime.

Lord Richards said Britain, America and France’s air strikes on Assad’s chemical weapons last weekend were “not quite token but minimalism” and “the jury is still out” on whether it would prevent the Syrian dictator using them again.

He is accused of being behind the suspected chemical attack that took place in Douma, near the capital Damascus, and killed scores of people.

Speaking on BBC Radio Four’s Westminster Hour, Lord Richards said the West should establish a protection zone in Idlib, a rebel outpost that Assad’s military is expected to attack next.

Richards, who was chief of the defence staff from 2010 to 2013, said this was “military doable”, despite British reluctance to do it and added he feared Assad was about to attack it, “which I think will lead to a lot of bloodshed”.

“Ten of millions of lives have been absolutely ruined… we should try to stop this war,” he said.

“Will Assad use chemical weapons again? I would have thought the jury’s out on that.

“It was the right thing to do, but I would have probably put a bit more effort into it though. I would have made it more punishing to ram home the requirement never to use chemical weapons again.

“You could have hit airfields, and other targets. This was designed to send a narrow lesson of punishment and not to risk any wider conflagration. 

“But the result is it’s a lost opportunity to change the course of the war.”

 He said troops should deploy to Idlib “in a defensive mode”.

“We’re not coming out to attack people from it, but we are not going to let you take Idlib,” he said. 

“Then Assad would have to factor that in to a calculation of some sort of negotiated peace down stream where he might have ended up back in charge of Idlib, but it would have been more on our terms.

“Those sorts of opportunities were missed last week, and I understand why.

“It is very complex. If it had gone wrong, it did risk rising tensions and maybe even a war with Russia of some kind.”

He added the Iraq War had “knocked confidence” and stopped Britain wanting to deploy boots on the ground.

  He added: “You can impact and influence war from the air and the sea but it’s people that live on land and therefore its’s there that you’ve actually got to commit military capability.

“If you’re not prepared to commit, you can’t be sure of the outcome. That’s the quandary we’ve got ourselves in.

“Until we develop the capability and the confidence, or find the cause that forces us to do it again, then I fear we’re in a position where we will risk ringing our hands rather self-righteously, but actually never do anything that will materially affect such awful things as the Syrian war.

He continued: “We’re probably just going to ring our hands and say, ‘just don’t use chemical weapons’.

“Well is that good enough?”