In the decade since reports surfaced that Iran was engaged in a program to enrich uranium and possibly to build a nuclear weapon, there have been periodic reports from intelligence agencies, US and Israeli officials, and outside analysts that Tehran would have a bomb in as little as a year or two. Ten years later: no bomb.

By the same token, over that period, there have been incessant reports by many observers—including Seymour Hersh in the New Yorker—that an attack by either Israel, the United States, or both on Iran’s nuclear facilities was imminent. Again, ten years later: no attack—although we know for a fact that in the waning years of the Bush administration Vice President Dick Cheney explicitly argued in favor of bombing Iran’s nuclear plants and research centers.

In the last weeks, once again, there are live rumors that Israel is readying an attack. Part of the reason why the talk is surfacing now may be that next week the International Atomic Energy Agency is set to release a new report which may report that Iran has made further progress in its nuclear program.

According to Haaretz, the liberal Israeli daily, Prime Minister Benjamin Netanyahu and Defense Minister Ehud Barak recently convinced ultra-hawkish Foreign Minister Avigdor Lieberman to support a military attack in the near future:

“Prime Minister Benjamin Netanyahu and Defense Minister Ehud Barak are trying to muster a majority in the cabinet in favor of military action against Iran, a senior Israeli official has said. According to the official, there is a “small advantage” in the cabinet for the opponents of such an attack. Netanyahu and Barak recently persuaded Foreign Minister Avigdor Lieberman, who previously objected to attacking Iran, to support such a move.”

A later piece in Haaretz reported that the cabinet is divided, with Netanyahu and Barak strongly in favor of doing so and Vice Prime Minister Moshe Yaalon opposed. Reported Haaretz:

A disagreement within the government over whether to attack Iran’s nuclear facilities has sparked a political catfight between two members of the “octet” forum of eight senior ministers: Vice Prime Minister Moshe Yaalon and Defense Minister Ehud Barak.… Yaalon and Barak presented diametrically opposed views: Barak supported an Israeli military strike on Iran and said it should take place as soon as possible, while Yaalon argued that Israel should give international sanctions on Iran more time, and that if military action did become necessary, it would be better for America to do it.

The new talk about an Israeli attack on Iran started with a column at the end of October by Nahum Barnea in the daily Yediot Aharanot, in which he wrote:

Have the prime minister and defense minister settled on a decision, just between the two of them, to launch a military attack on the nuclear facilities in Iran? This question preoccupies many people in the defense establishment and high circles of government. It distresses foreign governments, which find it difficult to understand what is happening here: One the one hand, there are mounting rumors of an Israeli move that will change the face of the Middle East and possibly seal Israel’s fate for generations to come; on the other hand, there is a total absence of any public debate. The issue of whether to attack Iran is at the bottom of the Israeli discourse.

Netanyahu has ordered Israel’s intelligence service to investigate the leaks, which some Israelis believe may have come from current or former members of those very same intelligence service. Earlier this year, retiring Mossad chief Meir Dagan warned that Netanyahu and Barak wanted to attack Iran, an action that he said he was unalterably opposed to. Reports Haaretz, citing—of all things, a newspaper in Kuwait:

According to the report, former Mossad chief Meir Dagan and former Shin Bet chief Yuval Diskin are those responsible for leaking information to the media regarding an attack on Iran.

The Jerusalem Post, a right-wing daily, helpfully fills in some details about what a strike might look like, reporting that it would involve “several hundred aircraft” and, possibly, the use of US-supplied bunker-buster bombs.

Needless to say, an Israeli attack on Iran would unleash catastrophic consequences, completely apart from whether or not Israel could actually do the job effectively.

Whereas Israel’s attack would be limited in scope and duration, an American attack on Iran would probably last four to six weeks, and it would target Iran’s air defense, air and naval units, military and intelligence command-and-control centers, bases of the Iranian Revolutionary Guard Corps, and important transportation and communication systems, along with weeks of pounding many of the more than fifty sites inside Iran involved in that country’s nuclear program. In contrast, Israel would likely be able to strike once, targeting only a handful of Iran’s most important sites, in Isfahan and Natanz.

But an Israeli attack would lead to a regional conflagration, in which Iran would use its proxies and allies and, most likely, terrorist units against US and Israeli targets across the region and even worldwide. Hezbollah, in southern Lebanon, would strike Israel, leading to what would end up being an Israeli war against both Syria and Lebanon. Iran’s allies in Iraq and Afghanistan could launch attacks against US and NATO forces there, and there’s a strong likelihood that Iran would try to attack the oil facilities of the Arab countries across the Persian Gulf. The ripples would spread from there, including soaring oil prices (in the range of $150 to $200 per barrel). For all these reasons, without definitive proof that Iran has actually acquired a bomb and that Iran is planning to use it, an attack by either the United States or Israel makes no strategic sense, especially since many analysts believe that even a sustained attack might not succeed in doing anything more than delaying Iran’s program while convincing Tehran to accelerate it and to move its facilities underground into hardened sites, as it appears to be doing in its new facility outside Qom.

President Obama, while pushing to isolate Iran and impose even tougher sanctions, isn’t likely to attack Iran. (That’s not true for some of his Republican rivals in 2012.) In addition, since 2007, under both President Bush and President Obama, the Pentagon has delivered strong warnings to Israel not attack Iran under any circumstances, because the consequences would be so severe. No doubt, those warnings stand. Which is why, for my part at least, I don’t believe Israel would risk an attack on Iran by itself.