Is it likely that Benjamin Netanyahu will announce at the United Nations that several Israeli aircraft have just returned from Iran? At first glance, no.

But worry over this issue doesn't stem only from the assurance given by the prime minister's friend, Dick Cheney, that Israel will attack; or from the messianic statements about a possible attack that Haaretz has recently quoted Netanyahu and Defense Minister Ehud Barak as making in closed forums; or from former Mossad chief Meir Dagan's warning that an attack will occur in the waning days of September in response to Israel's increasing international isolation; or from heightened anxiety caused by the imminent closure of the operational window of opportunity.

The fog must not be allowed to close in. Precisely because I have written about the conceptual necessity of carefully evaluating the effectiveness of activism in stopping a messianic bomb, it's clear to me that building Western, and especially American, support is a fundamental condition for even considering any implementation of an action.

This must be said, and clearly: No leader has either the moral authority or the strategic possibility of endangering tens of thousands of citizens before doing everything possible to make Israel beloved of the West. That is how Yitzhak Rabin made strategic decisions, while Barak at least talked about turning over every stone. And what exactly does Netanyahu intend to say to the thousands of bereaved families whose sons are not named Jonathan anymore?

A leader who genuinely believes that a bomb in messianic hands poses an existential threat must go even further than making Israel the first state to recognize Palestine in the 1967 borders. After all, even if the forecasts of that majority which is convinced of the folly of a strike prove wrong, it isn't a once-and-for-all solution: The need for a deep Western strategic rear goes way beyond spare parts and bunker-busting bombs.

These circumstances make any operational plan or option completely illegal - much worse than going to war in Lebanon in 2006 without any plans, supplies or reserve forces. The thought of launching an attack against Iran not merely without American and broader Western support, but from a situation of total political isolation and hostility, is so unsound that it calls into question the right to issue the order and the duty to carry it out. In these circumstances, anyone with the ability to stop it must stop it.

Today is the autumn equinox, when day and night are of equal length. The lengthening of the hours of darkness necessitates two additional notes of caution. The first relates to the UN General Assembly, and here, too, the obvious is being left unsaid. No Haaretz reader needs my permission to go to Paris; that's the definition of independence, including political independence.

So the Palestinians have every right to define themselves, especially in light of the fact that they are not demanding even a smidgen of sovereign Israeli territory and are open to territorial exchanges. Anyone who opposes Palestinian self-determination is undermining Israel's security.

One can understand the Evangelist Christians, who support a militaristic Israel with the sole aim of its being destroyed in a war of Armageddon against Iran and Iraq - a condition for the second coming of Jesus. But those who do not seek our destruction must be cognizant of Israel's interests. Anyone who acts otherwise, especially if he or she is Jewish, is kindly requested to send their children to Masada.

The third warning is addressed to Labor Party voters. If Israel survives the danger of Masada, it cannot live with a domestic conflagration. Herd voting in today's primary will not be forgiven. The voters must ask themselves whether the ballot in their hands was selected due to ethnic considerations.

Voters must also consider the announcement by Dalia Rabin-Pelossof, Rabin's daughter, that Amir Peretz is Rabin's successor: He supports money going to poor neighborhoods rather than West Bank settlements. Whether or not this declaration, by someone who has personal knowledge of the danger posed by Netanyahu, is accurate, the main question for every leader, and especially one aspiring to lead Labor, is whether he or she intends to do everything possible to stop Netanyahu on his way to Masada.