Israeli officials are warning they might have to launch an attack on Iran’s nuclear facilities, perhaps even before the U.S. presidential election in November. Israel’s concerns about a nuclear-armed Iran are well-founded, but this speeding up the timeline on a potential strike is ill-judged.

What is the sudden urgency? Nobody has been able to point to a recent game-changing event in Iran. Michael Oren, Israel’s ambassador to the U.S., was asked Wednesday by Bloomberg News whether it was tied to U.S. politics, the idea being that Israel might have more leverage to influence U.S. responses during an election campaign than after. He dismissed this.

If Israel is about to attack Iran (and this time the threats are backed up by distribution of gas masks and other civil defense preparations), then using the campaign season to pull in the U.S. makes tactical sense. Neither President Barack Obama nor Republican candidate Mitt Romney would want to alienate Jewish or evangelical Christian voters and donors by failing to support Israel. But it would also damage Israel’s most important strategic partnership. Nobody likes getting blackmailed.

The threats could, of course, be another bluff, designed to pressure the U.S. and Europe into quickly putting in place tougher sanctions. If so, that seems unwise, too. After so many unfulfilled warnings of an imminent attack on Iran, Israel’s credibility is eroding, not to mention the destabilizing effect on oil and other global markets.

Decision Maker

So what about the substance? Political considerations don’t matter if this is the right time to strike at Iran’s nuclear program. As an unnamed Israeli official (referred to as “the decision maker”) insisted in a recent Haaretz newspaper interview, a single atom bomb is enough to finish off the Zionist story.

According to this official’s calculation, Israel has at best until next spring before Iran has stockpiled sufficient nuclear material to reprocess into a bomb. By that time, Iran would have reached the point of immunity from Israeli attack. The U.S. would still be able to take action, with its greater capabilities, but understandably Israel does not want to outsource its essential security.

This is where the argument of the strike-now camp breaks down (which is why so much of the Israeli security establishment thinks this is not the time to attack, contra Defense Minister Ehud Barak and Prime Minister Benjamin Netanyahu). It’s very likely that go-it-alone airstrikes would make the situation worse for Israel. Haaretz’s “decision maker” (heavy hints in the piece suggest it was Barak) acknowledged that all Israel can hope to do is to delay Iran’s nuclear program. His estimate was six, eight or 10 years, by which time Iran might have a new regime.

U.S. and most military estimates are far less sanguine -- that it would set back the Iranians for two years at best. More important, it’s wishful thinking that an Israeli airstrike would lead to the fall of the government in Tehran. More likely, an Israeli assault would strengthen the regime, because the nuclear program is one of the few issues on which it enjoys broad-based support from an increasingly unhappy populace.

Past experience suggests Iran would also accelerate its nuclear program after being struck. Contrary to the general mythology, this is what happened in Iraq after Israel bombed the Osirak nuclear power plant in 1981. Iraqi nuclear scientists have confirmed in interviews that after the Osirak attack, Saddam Hussein threw thousands of scientists and billions of dollars into what had been a desultory nuclear weapons effort. It was the 1991 Gulf War and subsequent international sanctions that killed the program off.

Radioactive Uranium

An attack on Iran’s nuclear fuel infrastructure would need to target, among other things, the uranium conversion plant at Isfahan, a city of more than 3 million people. That would probably release several tons of toxic and radioactive uranium tetrafluoride and uranium hexafluoride into the atmosphere. It’s hard to know how many civilians would be affected, or how badly.

Iran would certainly retaliate. This week, Israel’s outgoing home defense minister, Matan Vilnai, estimated that Israeli airstrikes would be followed by a 30-day Iran-Israel war that would cost 500 Israeli lives, mostly due to Iranian missile strikes -- although he acknowledged that the death toll could easily be more or less. At a time of civil war in Syria and instability in Lebanon, the potential for wider fallout is real.

Finally, U.S.-led international sanctions, joined by Europe this year specifically to avert military action by Israel, might not survive an attack. Good luck getting the Europeans to stay committed, let alone persuading Japan and South Korea to agree to sanctions, if Israel strikes first. By contrast, a U.S. assault on Iran made after sanctions have been given a realistic chance to work stands a better chance of succeeding militarily and of keeping international pressure on Iran afterward.

Tough sanctions only took effect this year. It’s true they have not yet changed Iran’s behavior, beyond a brief visit to the negotiating table in the spring. They are, however, having an enormous impact inside the country. Iranian oil exports are down 52 percent this year, the rial has fallen sharply against the U.S. dollar, and the inflation rate has risen to 24 percent. The noose is likely to tighten further. The U.S. has given 20 important buyers of Iranian oil, including China, India and Japan, six-month waivers from U.S. punitive sanctions. The waivers come up for renewal in December. That’s the deadline Israel’s leaders should be focusing on, not November’s presidential vote.

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Today’s highlights: the editors on the U.S.’s ethanol policy; Stephen L. Carter asks whether anything is really “politically impossible”; Noah Feldman on Egypt’s democratic coup; William Pesek on reviving India’s economy; Amity Shlaes on lessons of the lobster trade; Jonathan Weil on Standard Chartered’s money laundering settlement; Adam Kirsch on presidential weakness in the novel “Primary Colors.”

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