But from the U.S. perspective I can say that the "existential" concept rests on two utterly unsupportable premises. One is that Iran is fundamentally like Nazi Germany, and the world situation of 2015 is fundamentally like that of 1938. Emotionally you can say "never forget!" Rationally these situations have nothing in common—apart from the anti-Semitic rhetoric. (To begin with: Nazi Germany had a world-beating military and unarmed Jewish minorities within its immediate control. Iran is far away and militarily no match for Israel.) The other premise is that Iran's leaders are literally suicidal. That is, they care more about destroying Israel than they care about their country's survival. Remember, Israel has bombs of its own with which to retaliate, so that any attack on Israel would ensure countless more Iranian deaths. As another reader, who also identified himself as Jewish, wrote:

Questions for Prime Minister Netanyahu (and his supporters) Question 1: How does Iran survive the consequences of a nuclear attack of any scale on Israel?

Question 2: There is no question 2.

That Iran's current leaders are zealots is easy to demonstrate. That they are suicidal? For that premise there is literally zero evidence, as Peter Beinart recently wrote and as Israel's own security-services report.

* * *

Maybe I am giving Netanyahu too much credit. Maybe he genuinely believes everything listed above—that he's been right all along, that we need to hear his message, that Obama and his administration will take no offense, and that this is a life-or-death existential issue because of a suicidal Iranian leadership.

Maybe. But I think he is smarter than any of that. And thus the explanation that rings truest to me is one offered in The National Interest by Paul Pillar, a veteran of the CIA. It's relevant to note that Pillar was as presciently right about Iraq, concerning both the hyped nature of the threat and the disastrous consequences of the invasion, as Netanyahu was spectacularly wrong.

Pillar's assessment is that the ramped-up "existential" rhetoric is a screen for the real issue, which is a flat contradiction between long-term U.S. and Israeli national interests as regards Iran. It is in American interests (as I have argued) to find some way to end Iran's excluded status and re-integrate it with the world, as happened with China in the 1970s. And it is in Israel's interests, at least as defined by Netanyahu for regional-power reasons, that this not occur. As Pillar writes:

The prime objective that Netanyahu is pursuing, and that is quite consistent with his lobbying and other behavior, is not the prevention of an Iranian nuclear weapon but instead the prevention of any agreement with Iran. It is not the specific terms of an agreement that are most important to him, but instead whether there is to be any agreement at all. Netanyahu's defense minister recently made the nature of the objective explicit when he denounced in advance “every deal” that could be made between the West and Tehran. As accompaniments to an absence of any agreements between the West and Iran, the Israeli government's objective includes permanent pariah status for Iran and in particular an absence of any business being done, on any subject, between Washington and Tehran.

That is, as long as Netanyahu keeps the attention on nukes and "existential" threats, he's talking about an area where the U.S. and Israel might differ on tactics but agree on ultimate goals. Inflammatory as that topic is, it's safer than talking about re-integrating Iran as a legitimate power, where U.S. and Israeli interests may ultimately differ. As George Friedman wrote in a Stratfor analysis just now:

This is the heart of Israel's problem. ... Israel does not want to be considered by the United States as one power among many. It is focused on the issue of a nuclear Iran, but it knows that there is no certainty that Iran's nuclear facilities can be destroyed or that sanctions will cause the Iranians to abandon the nuclear program. What Israel fears is an entente between the United States and Iran and a system of relations in which U.S. support will not be automatic.

From this perspective, Netanyahu's bull-headedness makes sense, even beyond its short-term electoral value back home. He can be willing to endure complaints about breach of protocol and partisan alignment, if in so doing he can prevent the deeper divergence in national interests from becoming apparent. And if this episode has any value on the American side, it may be to promote freer discussion of the many areas where U.S. interests align with Israel's, and those where they diverge. We'll see if that starts with the planned response by a number of Democratic representatives just after the speech.