What does it mean to be faced by an existential threat?
It means you, your family, your community, your city, your country and your nation could cease to exist at any moment based on the decision of another actor, over whom you have no control.
Add to this the fact that this other actor tells you at every opportunity that he aims, nay lusts, to destroy you and you begin to understand the predicament facing Israel today.
It's hard for Americans to understand this. We haven't faced such a threat for decades, since the height of the Cold War. But some still remember the civil defense drills of the 1950s and beyond. In the event of an atomic attack, people were taught to take cover under a table or next to a wall and to cover exposed skin.
As David Rothkopf, CEO and Editor-at-Large of Foreign Policy, wrote last month:
Since then, the notion that any single actor with any single act could effectively obliterate Americans or their lifestyle is very hard for many people to get their brains around.
But that is exactly the threat that Israelis face from even a 'limited' Iranian nuclear attack. And though it is reasonable to debate whether the Iranians would actually use such a weapon against Israel given the likely consequences for them, from the Israeli perspective, given Iranian threats and actions, the risks of guessing wrong about the intent of the leaders in Tehran are so high that inaction could easily be seen to be the imprudent path.
Some argue that a nuclear-armed Iran would be crazy to attack Israel, knowing that the response would be immediate and catastrophic for their own nation.
"Yes, a bomb in Tel Aviv would arguably be the end of Israel, while retaliation would destroy 'only' 20 million Iranians... But then, the very apocalyptic nature of the attack on Tel Aviv is what makes the threat of retaliation credible," wrote Bernard Avishai in The Daily Beast.
But what if he's wrong? What if there's a five percent chance that some Iranian leader at some point in the future could pull the trigger? Is a five percent possibility of utter annihilation acceptable for any Israeli leader?
In recent weeks, Iranian leaders have embarked on an almost unprecedented orgy of hate-speech. The Supreme Leader, Ayatollah Ali Khamanei, referred to Israel as representing a "cancerous tumor of Zionism in heart of Muslim world" and called Zionism a "danger for all humanity."
According to the Miami Herald, "Iranian President Mahmoud Ahmadinejad proclaimed that Israel's existence is an 'insult to all of humanity.' A couple of weeks earlier, he told a gathering of Muslim diplomats that, 'anyone who loves freedom and justice must strive for the annihilation of the Zionist regime.'"
Ahmadinejad told Muslim ambassadors in Tehran: "It has now been some 400 years that a horrendous Zionist clan has been ruling the major world affairs," saying the Jews control "the major power circles in political, media, monetary and banking organizations in the world."
Hitler would have been proud of such a speech. In fact, he could have written it -- with some minor editing. And that's just a small sample of the anti-semitism coming out of Tehran.
For much of the world, the Holocaust has now faded into history. But for Israelis, it is still all too real. Many Israelis have or had parents and grandparents who survived -- and many other relatives who did not. It remains living history.
What makes it worse is the sight of world leaders cozying up to Ahmadinejad. Dozens attended a summit of the Non-Aligned Movement in Tehran last month. The message they are sending through their attendance is that this kind of hatred is acceptable -- and that threatening genocide against Israel is not serious enough for them to stay away.
Do you suppose the world community will stir at this outrage? When "The Protocols of the Elders of Zion," the world's most notorious anti-Semitic forgery, is available in hotels in Jordan and on TV serials in Egypt, are there rounds of condemnations at the United Nations? Will Ahmadinejad no more be invited to international gatherings and symposia? Will the Muslim nations arise and say as one that we do not speak of people and nations in the manner? Will the world recognize that the Iranian leadership dreams of combining the two great warning signs of history, Hiroshima and Auschwitz?
No, this is what will happen: The furor will abate, the world will persuade itself that he doesn't really mean it, or he doesn't really have power. He will be applauded on the streets of Arab capitals, and the nations will swallow some sleeping draught composed of complacency, indifference, foolishness and a pinch of anti-semitism.
Prime Minister Benjamin Netanyahu now faces one of the toughest decisions any Israeli leader has ever faced. He knows the great cost, economic, diplomatic and not least in human life of an attack on Iran. But he simply cannot take the risk of allowing the Iranians to acquire the means to end the existence of Israel -- which would condemn the Jewish people to two Holocausts in the space of 80 years.
Follow Alan Elsner on Twitter: www.twitter.com/alanelsner