In normal circumstances, being American should have nothing to do with it. Dead is dead.
But this is different. There is no country in the world that gets more military aid from the United States than Israel. This amounts to billions of dollars worth of military aid every year. In the United States, we do without quite a bit because our resources are being wasted on pointless wars and on military aid to countries with dubious human rights records (Israel and Colombia are two examples of that).
If North Korea were to pull the same stunt and kill a few Americans, the United States government would be outraged and would be busy calling for sanctions from the United Nations.
But it's Israel that killed and injured Americans, Turks, and others. And the president only says that he "regrets" the loss of life???
Isn't it time to cut out the military aid to Israel... and use the resources to do something productive... a jobs program, better mass transit, health care...
As for the Americans killing a Canadian terrorist... well... I don't know about that... I don't have enough information... but the incident with a Canadian citizen who was detained by the United States and shipped to somewhere in the middle east (I think that it was Syria), where he was tortured... this was a terrible example of extraordinary rendition... a horrifying human rights violation... the Canadian government should have recalled its ambassador over that flagrant abuse.