So I recently saw a discussion regarding the Kurdish militias taking ISIS fighters prisoner and the rights or wrongs of the fact that the Kurds treated them (at the very least in front of the cameras) with the respect and dignity that would normally be accorded to opposing soldiers by an army that was a signatory to the Geneva Convention. Some people were outraged that the Kurds did this, some thought it a bit odd, and a handful agreed that it was appropriate.
I would say that I'm on the side that thinks this is appropriate. Now that may seem a barking mad position to take given what ISIS routinely does to its captives. But I think there are two reasons to support this position.
The first is that "an eye for eye" is the sort of knee jerk, ridiculous reaction I would expect of people like ISIS, not those claiming any kind of moral high ground in the contest. It is a fundamental, inescapable fact that if you follow this line of thinking then it will take you down a path that - through a series of slightly convoluted twists and turns - leads you inevitably to the conclusion that Jimmy Saville's children should be raped and/or molested by his victims, because "an eye for an eye" right?
The second is the much more practical purpose of what this approach would do for the Kurdish forces. Anyone fighting against ISIS should by now be under no illusions as to what will happen to them should they be captured by ISIS. Fighting tooth and nail to the last bullet and beyond is their only viable option. To surrender is to sign your own death warrant, and to willingly accept a potentially very gruesome end.
By comparison ISIS forces have a much less final choice. To surrender to Kurdish forces is to potentially save their lives, at the very least in the short term (I've no idea what the Kurds plan to do in the long run with any prisoners). This not only offers the Kurds the opportunity to end certain fights by offering terms of surrender to ISIS fighters, but it also encourages defection by fighters who don't see a long term future with the group.
As an example, intercepted messages sent back by a number of foreign fighters who travelled to Syria to join ISIS have demonstrated that actually taking part in a Jihad may not be all that they originally though it was cracked up to be. Complaints about being treated as slaves or kitchen skivs, no home comforts etc, have shown that not all ISIS fighters are the hard case Jihadists that they claim to be. As such, offering them a way out by surrendering can be tempting and potentially provides the Kurdish forces (and their western backers) with valuable sources of intelligence that could help hasten the end of the group.
As galling as it may be to watch men who have fought against them - and possibly carried out war crimes - receive water, food, medical care and decent treatment, it seems clear that the Kurdish forces understand that biting their lips and treating their enemy humanely is a long term investment that trades short term frustration for information and in some cases lower friendly casualties.