What do you mean by "ally", exactly? The US helps perpetuate the status quo in Saudi Arabia because the alternative is a descent into utter chaos in that country and its surroundings that would cause a catastrophe for worldwide energy supplies.
Also i think Iran is to similar as a culture to the us-evangelicals, to be ever "a reliable ally". Messianic (and thus innovative?!), having a drug problem and a "unwieldy" youth - and subtle racism. Nobody likes a mirror, when you are not in shape.
I didn't do anything, since I am neither a member of the US government nor even a US citizen.
I hope it's clear that given the chaos ISIS is causing in a resource-poor country, if they were running rampant in Saudia Arabia the world would be in for a couple of orders of magnitude worse time.