Don’t be complacent – Isis may have lost territory, but the battle is far from over

As has long been the case with the ‘war on terror’, this is no moment for rejoicing, still less for triumphalism

Some legitimate states embrace terror and terrorists – North Korea, the Taliban in Afghanistan, Gaddafi’s Libya – but it is unusual to witness a terrorist group creating their own viable nation state.

Or “caliphate” as Isis once styled its vast domains. At its height, this medieval death cult, astonishingly, ruled over large oil-rich swathes of Syria and Iraq, stretching from the border with Turkey almost to Iran and Jordan.

It was this scale of ambition that took almost every intelligence agency and observer by surprise (though not Patrick Cockburn, who warned the world about this terrifying new force in 2014).

No longer. The last few slivers of territory have been surrendered, and the fighters, as well as their wives and children (prominent among them Shamima Begum and her son) have been rounded up and placed in camps, there to await their fate.

It is unlikely that Islamic State’s warriors will be looked upon with great compassion by the Syrian, Kurdish or Iraqi authorities. After all, Isis burnt prisoners of war alive.

It would, though, be a mistake to declare “victory”, as Donald Trump has. Just as it was a grievously hubristic error of judgment for president George W Bush to plaster the slogan “Mission Accomplished” across an aircraft carrier after what he though was the end of the second Iraq war, so too is it now an error to think that these Islamists, the most extreme of the extreme, the most bloody of the bloody, will go quietly back to their homes and farms.

Like the Taliban in Afghanistan, Isis is far too well embedded in sections of Middle Eastern society, and thought, to ever be eradicated. All that can be done is to control and monitor them.

That is why it would be far safer for western security and regional peace to have the former Isis soldiers and their families – the likes of Ms Begum – repatriated to their countries of origin, distasteful a prospect as that might seem.

It is, quite plainly, the lesser of the two evils. In resisting their return, as the British and American governments seem to, is to invite them to become a permanent guerrilla army, pursuing asymmetric terrorist tactics against the regimes in Damascus and Baghdad, but also export their terror far and wide across the world.

Isis’s elimination from the map, paradoxically, will only make it “go global”, operating as the sort of terror “franchise” that al-Qaeda once did (and indeed Isis grew out of al-Qaeda). Isis can easily inspire without directing, copycat attacks of brutal cruelty anywhere and everywhere, from London’s Borough Market and the Manchester Arena to Morocco and the Philippines.

So Isis has not been defeated. Militant Islamist violence is capable of mutating into many forms, in order to take advantage of circumstances and evade destruction.

It has, in truth, already spread its ideology globally, via video nasties and the web. Why else would so many young people from Europe, North Africa and the Caucasus travel to fight its wars?

As has long been the case with the “war on terror”, this is no moment for rejoicing, still less for triumphalism and complacency. We are in no position to declare victory and move on. The best methods that can be deployed against Isis now are not bombs but intelligence and disruption to their supplies of recruits and funding.

The world – including Russia, Iran, Saudi Arabia and China – also needs to try and find a way of helping the Syrian people to rebuild their country without either subsidising president Assad’s government nor inadvertently seeing funds channelled to the continuing Isis, whatever it may call itself or its successors.

There are some 20,000 to 30,000 jihadis ready to serve their cause, trained and battle hardened, and unwilling to go home from Syria and Iraq. So long as Assad is in power they will have a ready focus for their activities. We have not heard the last of them.