The Caliphate shouldn’t be seen as a small group of Islamic fundamentalists or marginal extremists; it’s more like a series of concentric circles.

The hard, inner core – several tens of thousands strong – is made up of those prepared to commit brutal atrocities.
 
Around them is an inner circle, probably hundreds of thousands strong, who aren’t prepared to kill, but who fund and support the hard core.
 
Then there’s the outer circle, made of those who rather fancy the idea of a worldwide Caliphate and who, in many cases, hate the West for any number of reasons. That outer circle no doubt consists of many more.
 
All three circles operate within a world where the vast majority of Muslims firmly reject extremism and the associated Caliphate. But they do retain different values and perspectives, and many are instinctively hostile to our secularised culture; which means that an understanding, respect and acceptance for their beliefs and customs is critical to long-term success.
 
The key to defeating the Caliphate is to strip away the inner circle of support and convince the outer circle that brutal violence is not the way - to win the ‘battle of ideas’. And because, at its heart, this is a theological issue, the harsh truth is that ‘we’ will never win that battle of ideas; ultimately it has to be won by and within the Muslim world.
 
Applying hard, military power in order to contain and degrade the inner core will not ‘solve’ the problem - you do not destroy an idea by military power – and Christians should realise that more than most.
 
As a Christian in the military I have seen the reality of a fallen world; watching mass graves being dug up in the Balkans and Iraq; seeing what people can do to each other, has convinced me that words like ‘sin’ and ‘evil’ are not interesting theological issues – they are a harsh reality of a hard, brutal world.
 
So, in the same way that we need a police force in the streets to deal with domestic and international criminality, in my view we need to be prepared to deal with brutal dictators and organisations around the world - whether that’s Nazi Germany or the rise of the Caliphate.
 
And I’m not convinced that Jesus was a pacifist. In the upper room he tells the disciples to sell their cloaks and buy swords; and they take two with them to Gethsemane. That’s not the sign of a pacifist movement. Jesus tells them to lay down their swords because Gethsemane wasn’t the time or place to use them.
 
This being so, I think there are broadly four levels of military engagement that the West can follow. There is a hand’s off approach – supplying equipment, funding and training, as we’ve been doing for some time, although with limited results. There is direct but remote support, which means adding air strikes to supplies, but doesn’t integrate them with troops on the ground. This is the model we, more or less, adopted in Libya and Iraq and it is what Parliament agreed to this week for Syria. 
 
Then, there’s direct, integrated support, mentoring and fire-control teams planted in with ground forces, which we did in Afghanistan. The issue is, it’s not clear who we would work with in Syria – it would probably have to be either with the Syrian government’s military, or with one or more of the free Syrian opposition organisations.
 
Finally, there is full engagement, involving both ground and air forces. No one is seriously suggesting deploying western armoured divisions into Iraq or Syria, but we might well have to help the regional powers produce such a capability.  
 
The decision to extend UK air strikes against IS in Syria was a political decision – and an important one for various reasons. The military effect will certainly be helpful, but alone it will not change much. Military action must be set alongside a broader diplomatic, political and humanitarian strategy to win the ‘battle of ideas’ – a battle that can ultimately only be won by and within the Islamic world. This will take a very long time - so we need strategic patience – and the will to see things through. 

Major General Tim Cross CBE was commissioned into the British Army in 1971, having been an Army cadet from the age of 14. He served for a total of 36 years, and was involved in conflicts such as the ‘Troubles’ in Northern Ireland, the Gulf War, the Balkans and Kosovo War, and Iraq in 2003. A Lay Minister in the Church of England, he now works with a number of charities and humanitarian organisations – he chairs the Board of Theos – and is a visiting professor at three universities and an itinerant preacher and speaker. 

Image: commons.wikimedia.org