Frontline Fighting: The Brits Battling Isis, TV review: These foolhardy fighters might not be covered in glory but they're hard to forget

With constant news of British jihadists fighting alongside Isis, it's easy to forget others involved in the conflict: the amateurs on the frontline, battling to retake territory captured by the extremist group. It was three of these volunteers who were the subject of this fascinating film that stuck, with a disturbing ambivalence, in the mind.

The three were a motley crew: 22-year-old Jac, an IT worker from Bournemouth; Harry, 28, a former currency trader; and Jim, a 40-year-old former soldier. All had conviction in their motivations to fight "the greatest menace the word has ever faced", as Harry put it.

We saw them on operation in northern Syria. Like Our War, the BBC3 documentary series following British soldiers in Afghanistan, this was a frontline combat stripped down to its barest bones. Chest-mounted cameras and on-screen, rather than spoken narration, allowed full immersion; showing the arid, unprotected territory they worked in. When not fighting, the group filled their time smoking, or dancing in the case of the women (it is a mixed force). Then when the action came, we got frenetic, sweary, dusty scenes. It was painfully clear that, as Jim put it, these set-ups could lead to "a lot of fuck-ups".This point was hammered home when one of the number was shot in the stomach in a friendly-fire incident.

Yet this was a successful campaign, villages were "liberated". As cameras panned around the smouldering rubble of the freed territory, it was hard to share in the victory. Then we saw the detritus of terrorism – IED components, suicide vests – that served as a jolting reminder of the large-scale horror that has affected us all.

Up at the newly destroyed Isis HQ (decimated by US airstrikes, informed by intel from the group), the guys took pictures of the bodies on their phones for posterity. We learnt that seven of the militia had been killed in action since they left, but that two of our three were back fighting.

I didn't know whether to salute them for their commitment or shake them for the sheer foolhardiness and futility of it all. But I do know that this is a programme I won't forget in a hurry.