Dealing with Isis: Britain and the US are right to object to negotiations - but also not to insist too forcefully that others do likewise

To trade or not to trade? The tangled affair of the mooted exchange of a Japanese journalist and/or a Jordanian air force pilot – both held by Isis – for a woman terrorist sentenced to death by a Jordanian court has opened a new front in the debate over negotiating with the militant group that controls large swathes of Syria and Iraq. Having previously sought ransom for hostages, Isis was today demanding a prisoner swap, in a clear attempt to elevate its status as an actor with whom everyone must reckon.

This newspaper has long opposed the payment of ransoms, on the grounds that doing so only encourages terrorist groups to seize more hostages, while providing them with the financial means to expand their deadly activities. But both the US and Britain, the main proponents of this approach, have been sensible not to insist too forcefully that other countries, including some of their closest allies, do likewise. Now that prisoner exchanges are on the table, such tactfulness is even more sensible.

Imagine, for example, that Isis had captured not a Jordanian but an American air force pilot, or was holding a British soldier it wanted to swap for a couple of jihadists held in a UK jail. Only last year, let us not forget, the Obama administration traded five Taliban fighters from Guantanamo Bay for Bowe Bergdahl, the US army sergeant taken prisoner while serving in Afghanistan.

In Jordan, public clamour for action to secure the return of its pilot, Muath al-Kasaesbeh, has been intense. There is no reason to suppose that in comparable circumstances, a British or American government would find itself under any less pressure to “bring their boys back”. But the attendant risks would be great – greater than in the case of paying ransom.

In its interaction with the West, not least in the theatre surrounding the gruesome beheadings of US and British hostages, Isis has already shown that it can play its cards skilfully. The present case is more of the same, as the organisation manipulates deadlines, creating uncertainty and tensions among its foes and generating the maximum publicity for itself.

Prisoner exchanges, a practice probably almost as old as war itself, would undoubtedly raise its profile and “legitimacy” even more. The militants’ demand for the release of Sajida al-Rishawi, the suicide bomber involved in three attacks in Amman in 2005 in which more than 60 people died, should be seen in precisely this light. Those attacks were ultimately the work of al-Qaeda in Iraq, the group from which Isis originated. The return of Rishawi, therefore, would cement a historical legacy.

In Jordan meanwhile, earlier unsuccessful attempts by that government to secure its pilot’s return led to growing demands that the country simply quit the US-led coalition against Isis. Given Jordan’s geographical importance, as a base from which to launch air strikes, its withdrawal would be a serious blow to the alliance – quite apart from the message it would send to other wavering Arab members of the coalition. When it comes to sowing discord among enemies, Isis knows precisely what it is doing.

All of which makes it only more certain that the fight against the organisation will be long and gruelling. Some have hailed the recent expulsion of jihadist fighters from Kobani, on Syria’s border with Turkey, as a turning point in the struggle. In fact it was only achieved after four months of fighting, accompanied by the most sustained US air strikes of the war. The real lesson to be drawn is that this war cannot be won from the air, and that forces on the ground – Kurdish forces in the case of Kobani – are essential. Isis, in other words, will not be going away soon. Equally certainly, there will be many more hostage cases to remind us of that fact.