Interesting
Duh. I gave a rational basis and I stand by it.
Your requirements were good ones but too limited because of the moral responsibility angle. I think you fall squarely in the look the other way unless it impacts me directly camp. I think there are far too many conflicts and tyrants in the world for us to take them all on, but I think when the threat to us doesn't quite reach the they've already stuck a knife in us level the greater good angle can easily carry enough weight to cross the threshold. I certainly believe as well that your requirements 1 and 2 don't have to apply at all if the number of lives at risk by inaction is high enough (something like WW2 without any treaties).
Regards,
Mark