From a reader:

Jonah –
I agree with your point that US citizens are US citizens, and the can of whoop ass should be opened regardless of a murdered American’s religious affiliation – but I don’t think it is fair to attribute the increased US reaction to this latest bombing to what we do when non-Jewish Americans are killed in Israel. This was presumably a targeted attack, and that is the reason for the bigger reaction. If the US citizens killed in this latest bombing were Jewish, I suspect our reaction would be the same.
Best regards,
[Name withheld]