MPS WERE asked in 2013, to approve air strikes against Assad and in support of his opponents.

We refused to do so on the grounds that the outcome would have been similar to that in Libya – a strategic “own goal” – but with more bloodshed and the prospect of Assad’s chemical weapons falling into the hands of the Jihadis fighting against him.

Now we are asked to support the use of air power on the opposite side in the Syrian Civil War – against our deadly, selfproclaimed Islamist enemies.

This 180-degree shift is a step in the right direction.

Yet one vital question remains: who will supply the credible ground forces without which air strikes cannot be decisive?

IS can be driven out, but only if a credible force is assembled to do the fighting on the ground.

This must be with at least the acquiescence (if not the co-operation) of Russia and her client, the Syrian government; and the force would have to remain as an occupying power for several years to come. That is why it needs to be a Muslim force, not a so-called “infidel” one.

If the prime minister proposes an integrated plan to help a suitable force drive out IS and remain in control, then that will be a strategy which I can support.

The Kurds alone will not be sufficient, other extreme Islamist groups will not be acceptable.

Bombing on its own will not be effective – and will remain ineffective in the absence of appropriate ground forces.

If military intervention is to succeed, a multi-national force must be assembled.

We should oppose mounting air strikes unless and until that happens.

JULIAN LEWIS New Forest East MP and chairman of the Defence Select Committee