For some reason, a disproportional number of our Afghan "allies" have not gotten the memo that we are allies.
The real disgrace here is that there is a mealy-mouthed euphamism for these murders: "green on blue". The Afghanis just "turn their weapons" the wrong way. No biggie.
Gen. John Allen, the commander of the NATO-led International Security Assistance Force, referred last month to "an erosion of trust that has emerged from this," .
I would say that murdering your fellow soldier is a relatively significant "erosion of trust".
More "explanation":
"Disputes can arise from cultural misunderstanding, religious and ideological friction or combat stress, said Brig. Gen. Stephen Townsend, director of the Pakistan-Afghanistan Coordination Cell in the U.S. Joint Chiefs of Staff office."
Townsend said cultural training has been vital for U.S. soldiers, and now the Afghan authorities are considering the same to provide a better understanding of Americans.
We're screwed.