Juan Cole clearly describes the harm done to American interests by the actions of our Israeli allies:
I am upset about the renewed crisis in Palestine because it is an emotional issue and will spill over into Sunni Arab Iraq. It is likely that pro-Palestinian Sunni guerrillas will kill some US troops specifically to avenge the people of Gaza. This is one reason I am complaining about the massively disproportional character of the Israeli response. It has the potential of further endangering American lives in the region.
Personally, I don’t see how knocking out power to half the population of Gaza will lead to the release of the kidnapped Israeli soldier. Collective punishment is a war crime that neither the US nor the UN should ignore.