You say “It needs to be stopped now, before it gets any worse.” and then admit that “All put the United States in an untenable, negative sum situation where, regardless of what we do, we will come out on the short end of the stick.” So, whether “it” is “stopped” or not, the U.S. goose is cooked – because a nuclear armed Iran is a clear and present danger to the U.S. and its interests, and steps which could have been taken by us over the last decade to derail this deadly project were delayed or derailed. While the U.S. could repeat the mistakes it made in trying to isolate itself from the “European War” in 1939, in the end we will have to fight to maintain our freedoms and our way of life, against the resurgent Islamists who seek to dominate us, and the world, and drag everyone back to the 9th Century.

As far as Israel is concerned, again, you are correct. Perception is reality. And Israel perceives any enemy, especially one led by such irrational theocrats as Iran, that threatens and has the wherewithal to realize its threat to annihilate the country and its population, as an existential threat. Even if Iran were to simply threaten use of a nuclear weapon, the threat in itself is an existential risk. For Israel devoid of any natural resources, beset by natural obstacles in climate and environment, has but one resource – its human resource and the brainpower behind it. If that human resource, the brightest and the best, feel that life under constant threat is untenable, there are a host of more welcoming locations that would love to attract all those future Nobel Prize winners away. Israel cannot afford to allow that to happen. It would, again, be the end of the nation state of the Jewish People, (and likely of the Jewish People themselves within a few short generations.)

So yes, the acquisition of nuclear capability by a government that has repeatedly promised to exterminate Israel, in so many words, can and should be considered an “imminent threat” which demands a “preemptive strike”, before the immunity that such acquisition would provide is realized.

Finally, the question is not whether an Israeli attack, if it were to come to pass, with or without U.S. involvement is “good” for the U.S. The question is if there is no attack, and Iran possesses nuclear weapons, what will the risk, and consequences to the U.S. and its interests be then?