Dr. Olli Heinonen, former deputy secretary general of the International Atomic Energy Agency, presented a relatively optimistic forecast regarding the Iranian nuclear danger when speaking with Haaretz last month. Iran's centrifuges, he told Yossi Melman, are not working well; some of them are defective. Only about 3,000 are working properly, and Iran will need many more to enrich uranium to a level that will allow it to manufacture a nuclear weapon.

Intentionally or not, Heinonen provided a significant argument against an Israeli attack on Iran's nuclear sites in the near future. Heinonen is talking about a critical period of more than a year, during which diplomatic efforts can still see the program halted. A host of international media reports about computer worms and mysterious explosions of Iranian nuclear sites and missiles, responsibility for which has been attributed to various intelligence agencies in the West, could attest to even more time available before a violent clash becomes inevitable.

The scenario presented by Jeffrey Goldberg in The Atlantic, depicting in detail a possible Israeli attack, naturally made waves worldwide and in Israel. But along with the limited progress of the Iranian nuclear program, other considerations must be taken into account. The main one involves the implications of an Israeli military move. The immediate outcome of such a move would be a missile war with Iran and its proxies in the region, Hezbollah and Hamas, into which Syria might be swept.

A plan that might seem impressive on a screen before the seven senior cabinet members who meet might deliver much less than promised in practice. The danger is that Israel will obtain only a short-term delay of the Iranian bomb, but will get involved in a prolonged war.

Another important consideration involves the response of the United States. Relations between U.S. President Barack Obama and Prime Minister Benjamin Netanyahu are terrible. Just awful. Obama is angry at Netanyahu because the latter did not accede in time to his pressure and agree to another construction freeze (a gesture he might agree to now ), and because of the actions of Netanyahu's supporters in Washington that helped Obama's opponents in Congress.

After the mid-term elections, the time will come to settle the score. It seems that Netanyahu's hard-line supporters forget Israel's great dependence on the United States.

What is true in ordinary times is even more true in wartime. Israel needs the Americans: for an "air corridor" for an attack, for surveillance and missile defense, for diplomatic support and an airlift of weapons and spare parts.

It is not surprising that the administration last week rejected Netanyahu's demand that the Americans highlight the military option against Iran. Obama's predecessor George W. Bush wrote in his memoir that he turned down Prime Minister Ehud Olmert's request that the United States and not Israel attack the Syrian nuclear facility in 2007. At this time it is hard to imagine that a hypothetical Israeli notice of a planned attack on Iran would get even a yellow light from Obama.

The security establishment has probably invested a fortune and a huge number of man-hours over the Iranian threat. The army must plan for the worst-case scenario, lest it come about. The extensive coverage worldwide of the preparations for a possible attack help deter Iran. In any attack plan of any country there is a risk that the pilots, and particularly the leaders above them, will become enthralled by the plan, without considering all the implications. A wise man once described the overemphasis on the Iranian issue as "idolatry."

The Netanyahu government is at a diplomatic dead end; partly by its own fault and partly by the fault of its neighbors. Syria did not meet Israel's expectation that a diplomatic agreement would include a break between it and Iran and that Damascus would cease stirring the pot in Lebanon. The Palestinian Authority leadership now has more sympathy and understanding than does the Israeli government in the capitals of Europe and the United States. That is trouble that Israel must find a way to get out of, but not by pressing the accelerator toward Iran.