If Russia's proxy secessionists shot down the plane (as it seems), it was surely a mistake.
So I'm not sure this is a war crime rather than a horrible accident.
Perhaps the manner of targeting--if the shooters failed to do what rules of war require to distinguish between a military target and civilians--makes it a crime.
But isn't the bigger crime that Putin invades Ukraine to capture Crimea; and is trying to seize eastern Ukraine by a proxy war?
I find it a little stunning that the whole war of Russian aggression against a member of the sainted international community in violation of the UN charter and other international agreements isn't sparking outrage while an incident that flows from the aggression suddenly sparks outrage.
UPDATE: Ah, there could be problems with the targeting process:
If a missile was fired without attempting to identify the aircraft, the destruction of Malaysia Flight 17 would be an act of criminal negligence, said retired U.S. Air Force Maj. Gen. Robert Latiff.
So it could be a war crime. Remember, too, that there was no heat of the moment excuse since that plane was at such a high altitude that it wasn't any threat to the shooters.
UPDATE: And Applebaum beat me to the basic point:
Before there is any further discussion of Malaysia Airlines Flight 17, it’s important that one point be made absolutely clear: This plane crash is a result of the Russian invasion of eastern Ukraine, an operation deliberately designed to create legal, political and military chaos. Without this chaos, a surface-to-air missile would not have been fired at a passenger plane.
Yet even Appleabaum misses the point that Russia's invasion started not with eastern Ukraine, but with Crimea--which Putin still controls.
Amazing. How short is our attention span?