Or alternatively the ISAF hierarchy could try to encourage integration between all the national forces under its command. Its not every soldier or police officer that commits these crimes, it is usually a disgruntled serviceman unhappy with his situation and feeling the need to lash out or a mole, a member of the taliban or taliban sympathizer who joined with the intention of planning a strike.
Simple things like speaking some basic phrases of Pashtu or Dari, having a little cultural understanding and just talking to the local national forces can have a very positive effect.
Its good to get a rapport going with the local forces, we used to play vollyball and football with them and share some duties that forced us to interact.
I was lucky enough to be enrolled on a Pashtu course before i went over and it helped a lot, i got on very well with all the Afghan interpreters and every ANA soldier i met, little things like taking an hour out of my own time to locate some nails and help put a roof back on the FOB mosque, ensuring at least one of the power supply cables for leisure use went to their part of the camp, when i brought a drink i got one for the ANA guys aswell, not just the Brits or just talking to them, learning their names and having little conversations its all beneficial for 2 reasons.
First they get to know you and you get to know them, it means they're more likely to tell you things when your on patrol, usually they just shout to each other, but once they got to know me they would pass information on to me as well which i could then pass on to the rest of the British men on the patrol.
Second, if there is a bad egg you can sense them out, working with the ANP i did come across some drug use and discussed it with am interpreter before i took it to the chain of command because you have to understand the group you are dealing with, the ANP is a very different organization to the ANA and the professionalism of the ANP can vary from village to village.
What i felt when working with the ANA is that they were a fledgling Army eager to prove themselves, one guy, he was in his 40's and had 2 sons also in the ANA would always make jokes about how we didn't kill enough taliban with our good rifles and that if we gave him our rifle for a day he would kill 100 taliban.
The ANP was a different story, the ones i met never wore full uniform, if they wore any uniform at all, they were highly unprofessional and seemed to resent being told what to do or instructed on anything, there was one lad who did seem keen but he also seemed to bare the brunt of all the work due to his willingness :/
I don't think they're ready yet, but the ANA is getting there, personally i would scrap the ANP.