KABUL, Afghanistan – The U.S. military trainers handed the new recruit, Mohammad Ismail, his AK-47 to defend his remote Afghan village. He turned around and immediately used it, spraying the Americans with bullets and killing two – the latest of nine U.S. service personnel gunned down in two weeks by their supposed allies.

The shooting in Farah province was not the only such attack Friday. Hours later a few provinces away in Kandahar, an Afghan soldier wounded two more coalition servicemen.

One turncoat attack per month raised eyebrows last year. One per week caused concern earlier this year. But when Afghan forces turn their guns on international trainers twice in a day – as they now have two weeks in a row – it’s hard to argue there’s not something going on. The question is, what is it?