1967 protests against the resignation of Egypt’s Gamal Nasser. (Wikimedia Commons)

You are the leader of a strong Middle Eastern state. You have fairly solid intelligence that your most formidable adversary is about to acquire nuclear weapons. The leaders of this rival nation, while uttering pious but ambiguous statements to the contrary, have spared no effort to ensure that no one believes them. The superpower friendly to this incipient nuclear state goes through the motions of opposing the nuclear project, but it is unlikely to exert meaningful pressure or enforce effective sanctions. To your consternation, your own superpower ally has abruptly shifted its approach and has tried to engage this hostile neighbor—to no avail. A bomb in your enemy’s possession will change the rules of the neighborhood rivalry dramatically and irrevocably to your disadvantage; in public statements, you charge that it will pose an existential threat to your country. Now that you have learned the program’s fruition is imminent, should you take advantage of the shrinking window of opportunity and strike, regardless of any collateral consequences?

In mid-1966, this was the dilemma faced by Egypt’s Gamal Abdel Nasser, when he received—from his Soviet backers and others—convincing reports that Israel was about to cross the nuclear threshold.

A mild disclaimer is in order here: We are not comparing, much less equating, Israel and Iran, nor the character and purposes of their respective nuclear programs; indeed, we have no first-hand knowledge of the Israeli project, much less the Iranian one. What we researched, and where we found intriguing parallels with the present day, is how the Israeli nuclear enterprise was perceived and counteracted by the Egyptians and Soviets. In our book Foxbats Over Dimona: The Soviets’ Nuclear Gamble in the Six-Day War, we described how fear of an Israeli nuclear bomb became a central motive for their joint, deliberate instigation of a crisis designed to precipitate a war in May and June of 1967.

One salient difference between these two cases is in the role of the global actors. Even the recent leak of a paper by U.S. Secretary of Defense Robert Gates decrying the lack of an effective U.S. policy to prevent Iran’s nuclearization was quickly followed by a clarification from the Joint Chiefs of Staff chairman that military action would be the last option to fill this gap. This did not exemplify a shift under the administration of President Barack Obama. Washington—correctly in our view, though perhaps for the wrong reasons—stopped brandishing military threats against Iran in the George W. Bush years. Since then, a succession of U.S. messages and messengers to Israel has reportedly been aimed at restraining any warlike intentions on the latter’s part.

In the mid-1960s, once the Soviet Union had evidence from Israeli and other sources that Israel was intent on producing or acquiring a bomb, Moscow briefly tried to engage Israel much as Obama has tried with Iran—in fact, the Soviets, with an embassy in Tel Aviv and good contacts in Israel, were better positioned to do so than the Americans are today in Iran. But Israel effectively rejected Soviet proposals of a WMD-free zone around the Mediterranean (which, Israel said, it could risk only if conventional weapons were barred too). Egypt and other Arab states, on the other hand, strongly protested the modest concessions that Moscow offered to Israel in return, such as improved cultural and scientific exchanges, which the Arabs saw as an ominous pro-Israeli swing by the Soviets. They raised an outcry, and the USSR relented; the carrot that it had dangled in front of Israel was replaced by a very big stick.

The Soviets had their own reasons to want to halt Israel’s nuclear development. One was a matter of regional influence. Only 11 years earlier, a thinly veiled nuclear threat from Moscow had been instrumental in forcing Israel’s withdrawal from Sinai, which it had captured from Egypt in a joint military campaign with Britain and France. Historians still argue whether it was the Soviet nuclear threat or U.S. diplomatic pressure that actually did the trick—but the Soviets themselves and their Arab protégés chalked up all the credit to the USSR. Moscow’s standing in the Middle East was enhanced by the threat of a nuclear strike to back up its clients’ interests, thus increasing their dependence. This advantage would be canceled out if Israel achieved a nuclear counter-deterrent.

But the Soviets evidently perceived Israeli nukes also to be a direct threat to their own territory, especially once it was reported that the Israelis had contracted to buy French missiles that could reach the southern USSR. Moscow had a deep-seated fear of encirclement by nuclear-armed pro-American alliances. From its 1962 setback in Cuba, it had salvaged the withdrawal of U.S. Jupiter missiles from Turkey. Now it seemed that Israel would replace Turkey in the encircling U.S.-led nuclear alliance.

In addition, after assisting China to acquire the bomb—and then regretting it—the Soviets adopted a firm nonproliferation line and had no desire to face future demands for the bomb from Egypt or other Arab clients. This obliged them, in mid-1966, to grant Nasser an alternative: a Soviet nuclear “umbrella,” carried by Soviet nuclear submarines in the Mediterranean, which had orders to launch missiles at Israel if it got a bomb and tried to use it, an arrangement much like what the United States is promising its Middle Eastern clients today.

More important for this analysis, the Soviets not only signaled that they would support Egyptian military action to halt Israel’s nuclear development, they also embarked on planning a joint strike that would take out Israel’s main nuclear facility at Dimona. This direct Soviet intervention was not limited to the nuclear objective; it was also designed to ensure a defeat for Israel on the ground that would drive it at least to the borders of the 1947 U.N. partition (which the USSR had supported and was still committed to) and force it to renounce any future nuclear aspirations.

These dramatic Soviet aims were to be achieved by supporting Egyptian and Syrian invasion forces and air attacks with a Soviet naval landing, a paratroop drop, and Soviet strategic (but conventional) bombing of Dimona and other Israeli targets. By contrast, an invasion of Iran to compel its surrender, or even an air offensive overwhelming enough to topple its regime, is unthinkable today in terms of U.S. capabilities and inclinations, let alone Israel’s. In 1967, the Soviets were aiming for more.

Moscow insisted both on maintaining the appearance of legitimacy and on minimizing the risk of a direct confrontation with the United States. The Soviets therefore preferred that Egypt take a series of belligerent measures against Israel without actually opening fire; the signal to begin these steps was a false Soviet warning about Israeli forces massing on the Syrian border, which Moscow transmitted to Cairo 43 years ago last May. The Israelis would be provoked into a preemptive strike, which the Soviets calculated that Egypt could contain in the expanses of Sinai. The Israeli first strike that determined the later course of what became known as the Six-Day War was therefore a key part of Soviet strategy. Once Israel was condemned as the aggressor, the USSR believed it could intervene in favor of the victims—since Moscow correctly reckoned that Washington would make good on repeated cautions to Israel that if it shot first, it would stand alone.

Israel’s prime minister in 1967, Levi Eshkol, has gone down in most histories of the war as hesitant and indecisive in responding to Nasser’s Soviet-instigated measures (moving his army into Sinai, expelling the U.N. force from the border zone, and blockading Israel’s southern port). But Israel’s temporizing brought Egyptian-Soviet tensions to the surface; the Egyptians rightly feared that they would not be able to withstand an Israeli offensive and sought clearance to strike first, according to a battle plan that was later captured in Sinai and included an air attack on Dimona. The Soviets demurred and insisted that Egypt await Israeli action. In order to provoke an Israeli response, the Soviets sent their most advanced, still-experimental, and secret aircraft, later to be known as the MiG-25 or Foxbat, on two sorties over Israel’s most sensitive and guarded installation—the nuclear complex. The Israelis had nothing to match the Foxbat’s speed or altitude, the targeting and vulnerability of Dimona was demonstrated, and the fright this caused in Israel went a long way toward its decision to go to war on June 5—just as Moscow intended.

Then Murphy’s Law took over, and the Soviet-Egyptian effort went horribly wrong. The unexpectedly devastating effect of Israel’s opening air raids on Egyptian air bases not only deprived the Egyptian forces of air cover, they also prevented Soviet bombers from landing on Egyptian runways. Under such conditions, the Egyptians’ anxieties were borne out: The Middle East’s first nuclear war (that is, the first war about nuclear weapons) turned into a historic disaster for the Soviets and their clients alike.

An Israeli strike on Iranian nuclear facilities—even with U.S. backing or participation—would be undertaken under circumstances considerably less favorable than those enjoyed by Moscow and Cairo in 1967. For one thing, the USSR almost certainly had better intelligence assets in Israel than either the United States or Israel appears to have in Iran—or else their assessments of Tehran’s nuclear progress and intentions would not have fluctuated as wildly as they have. The Soviets evidently received good field reports from Israel, but their interpretation was skewed at the top to meet political expectations, a problem that is not unfamiliar elsewhere.

We do know that Iran’s program is widely dispersed, while Israel’s was concentrated at one site. So was Iraq’s nuclear project when Israel attacked it in 1981. Though successful, that raid only delayed the Iraqi effort. Hindsight shows it took a full-scale war and imposition of external control to end it 10 years later, and, even afterward, Saddam Hussein managed to keep up appearances so well that a nuclear threat could wrongly but successfully be invoked to justify another war in 2003.

Most important, Iran today has far greater capability to strike back at Israel than Iraq did in 1981, or than Israel had in 1967 to strike back at the Soviet Union or even at neighboring Arab states. Together with Iran’s geographic distance from Israel, these capacities will permit Tehran to retaliate with impunity. The recently reported transfer of Scud missiles from Syria to Hezbollah underlined the almost-complete coverage of Israel’s population centers by short- and mid-range rockets possessed in vast quantities by this Iranian-sponsored Shiite group, along with the smaller stocks possessed by Hamas in Gaza. The sporadic, but almost daily, launch of a rocket or two from Gaza into southern Israel has become so routine that it hardly makes the local news, much less the world media. But it demonstrates that Israel has yet to achieve and deploy an effective defense against the least-sophisticated types of such weapons. Obama—despite accusations of a policy tilt against Israel—has proposed, and Congress has just approved, U.S. funding to accelerate the deployment of Israel’s Iron Dome anti-rocket system. But even once installed, Iron Dome would provide only partial protection against massive volleys of short-range rockets, if only because it pits an advanced, costly projectile against each crude, cheap incoming round.

We agree wholeheartedly that a bomb in Iranian hands would be pernicious in many ways and that it should be prevented by any reasonable means if not at all cost. We doubt, however, whether this can be accomplished. The new sanctions package that was at last adopted by the U.N. Security Council had to be watered down to the point of doubtful effectivity in order to gain Russian and Chinese consent. Even so, the countries have since been blowing hot and cold about their compliance—and its practical significance remains in question, especially in respect of such vital aspects as energy, banking, and supply of air-defense systems that might doom any attack plan. Persuading the Iranians by other means that forswearing the nuclear option would be better for them is definitely worth a try, but the prospects are dim.

Like it or not, then, it looks as though we will have to contend with a nuclear-armed Iran. Are the ayatollahs rational enough to be contained and deterred by Israel’s pre-existing nuclear reputation, not to mention U.S. overt and overwhelming power? Once the Iranians cross the threshold, will the region settle into an unfortunate but manageable balance of terror—or will they toss their bomb at Israel regardless of the national and personal suicide it means? Our historical research offers no clear answer to this question, and the two of us hold different opinions that are no better informed than those of other lay observers. What we did learn from studying the mistakes of the Egyptians and Soviets in 1967 is that embracing any option, and especially a massive military intervention, just because something has to be done is a potentially calamitous way to conduct policy—the first rule of warfare being that whatever can go wrong will go wrong.

At a conference in Washington last October, our faces must have betrayed our dismay when a panel including a U.S. general and his Israeli counterpart came within an inch of explicit calls to bomb Iran forthwith. Someone at our table, clearly exhilarated by the prospect, noticed and asked our opinion, which was “heaven forbid.” “So, you’ve been deterred!” he sneered. You bet.

Isabella Ginor and Gideon Remez are research fellows at the Truman Institute of the Hebrew University in Jerusalem. Their book, Foxbats Over Dimona, won the Silver Medal in the inaugural award of a new book prize from the Washington Institute for Near East Policy.