On June 7, 1981, eight Israeli F-16 fighter jets, protected by six F-15 escorts, dropped 16 2,000-pound bombs on the nearly completed Osirak nuclear reactor at the Tuwaitha complex in Iraq. Israeli Prime Minister Menachem Begin and Defense Minister Ariel Sharon saw the reactor as central to Iraqi President Saddam Hussein’s quest to build nuclear weapons, and they believed that it posed an existential threat to Israel.

The timing of the strike was justified by intelligence reports suggesting that Osirak would soon become operational. Two days later, Begin explained the raid to the public: “We chose this moment: now, not later, because later may be too late, perhaps forever. And if we stood by idly, two, three years, at the most four years, and Saddam Hussein would have produced his three, four, five bombs . . . another Holocaust would have happened in the history of the Jewish people.”

Three decades later, eerily similar arguments can be heard regarding the threat of a nuclear-armed Iran. Last May, Israeli Prime Minister Benjamin Netanyahutold a joint session of the U.S. Congress that “the hinge of history may soon turn, for the greatest danger of all could soon be upon us: a militant Islamic regime armed with nuclear weapons.” In a Feb. 2 speech in Israel, Deputy Prime Minister Ehud Barak channeled Begin in making the case for possible military action against Iran, arguing that “those who say ‘later’ may find that later is too late.” And late last month, Barak sought to discredit Israeli President Shimon Peres’s reported opposition to a possible strike on Iran by pointing to his dissent during the 1981 attack.

When Netanyahu meets with President Obama on Monday and addresses the annual meeting of AIPAC, the American Israel Public Affairs Committee, later that day, we should expect additional dire assessments and warnings of military action.

For Israelis considering a strike on Iran, Osirak seems like a model for effective preventive war. After all, Hussein never got the bomb, and if Israel was able to brush back one enemy hell-bent on its destruction, it can do so again. But a closer look at the Osirak episode, drawing on recent academic research and memoirs of individuals involved with Iraq’s program, argues powerfully against an Israeli strike on Iran today.

To begin with, Hussein was not on the brink of a bomb in 1981. By the late 1970s, he thought Iraq should develop nuclear weapons at some point, and he hoped to use the Osirak reactor to further that goal. But new evidence suggests that Hussein had not decided to launch a full-fledged weapons program prior to the Israeli strike. According to Norwegian scholar Målfrid Braut-Hegghammer, a leading authority on the Iraqi program, “on the eve of the attack on Osirak .?.?. Iraq’s pursuit of a nuclear weapons capability was both directionless and disorganized.”

Moreover, as Emory University political scientist Dan Reiter details in a 2005 study, the Osirak reactor was not well designed to efficiently produce weapons-grade plutonium. If Hussein had decided to use Osirak to develop nuclear weapons and Iraqi scientists somehow evaded detection, it would still have taken several years — perhaps well into the 1990s — to produce enough plutonium for a single bomb. And even with sufficient fissile material, Iraq would have had to design and construct the weapon itself, a process that hadn’t started before Israel attacked.

The risks of a near-term Iraqi breakthrough were further undercut by the presence of French technicians at Osirak, as well as regular inspections by the International Atomic Energy Agency. As a result, any significant diversion of highly enriched uranium fuel or attempts to produce fissionable plutonium would probably have been detected.

By demonstrating Iraq’s vulnerability, the attack on Osirak actually increased Hussein’s determination to develop a nuclear deterrent and provided Iraq’s scientists an opportunity to better organize the program. The Iraqi leader devoted significantly more resources toward pursuing nuclear weapons after the Israeli assault. As Reiter notes, “the Iraqi nuclear program increased from a program of 400 scientists and $400 million to one of 7,000 scientists and $10 billion.”

Iraq’s nuclear efforts also went underground. Hussein allowed the IAEA to verify Osirak’s destruction, but then he shifted from a plutonium strategy to a more dispersed and ambitious uranium-enrichment strategy. This approach relied on undeclared sites, away from the prying eyes of inspectors, and aimed to develop local technology and expertise to reduce the reliance on foreign suppliers of sensitive technologies. When inspectors finally gained access after the 1991 Persian Gulf War, they were shocked by the extent of Iraq’s nuclear infrastructure and how close Hussein had gotten to a bomb.

Ultimately, Israel’s 1981 raid didn’t end Iraq’s drive to develop nuclear weapons. It took the destruction of the Gulf War, followed by more than a decade of sanctions, containment, inspections, no-fly zones and periodic bombing — not to mention the 2003 U.S. invasion — to eliminate the program. The international community got lucky: Had Hussein not been dumb enough to invade Kuwait in 1990, he probably would have gotten the bomb sometime by the mid-1990s.

Iran’s nuclear program is more advanced than Hussein’s was in 1981. But the Islamic republic is still not on the cusp of entering the nuclear club. As the IAEA has documented, Iran is putting all the pieces in place to have the option to develop nuclear weapons at some point. Were Supreme Leader Ayatollah Ali Khamenei to decide tomorrow to go for a bomb, Iran probably has the technical capability to produce a testable nuclear device in about a year and a missile-capable device in several years. But as Director of National Intelligence James Clapper told the Senate Arms Services Committee on Feb. 16, it does not appear that Khamenei has made this decision.

Moreover, Khamenei is unlikely to dash for a bomb in the near future because IAEA inspectors would probably detect Iranian efforts to divert low-enriched uranium and enrich it to weapons-grade level at declared facilities. Such brazen acts would trigger a draconian international response. Until Iran can pursue such efforts more quickly or in secret — which could be years from now — Khamenei is unlikely to act.

Also, an Israeli strike on Iran’s nuclear infrastructure would be more risky and less effective than the Osirak raid. In 1981, a relatively small number of Israeli aircraft flew 600 miles across Jordanian, Saudi and Iraqi airspace to hit a single, vulnerable, above-ground target. This was no easy feat, but it is nothing compared with the complexity of a strike on Iran’s nuclear infrastructure.

Such an attack would probably require dozens of aircraft to travel at least 1,000 miles over Arab airspace to reach their targets, stretching the limits of Israeli refueling capabilities. Israeli jets would then have to circumvent Iranian air defenses and drop hundreds of precision-guided munitions on the hardened Natanz enrichment facility, the Fordow enrichment site deep in a mountain near Qom, the Isfahan uranium-conversion facility, the heavy-water production plant and plutonium reactor under construction at Arak, and multiple centrifuge production facilities in and around populated areas of Tehran and Natanz.

These same aircraft would not be able to reengage any missed targets — they would need to race back to defend Israel against retaliation by Iran and its proxies, including Lebanese Hezbollah and possibly Hamas.

Unlike an attack by the U.S. military, which has much more powerful munitions and the ability to sustain a large-scale bombing campaign, an Israeli assault would probably be a one-off strike with more limited effects.

No wonder that Gen. Martin Dempsey, the chairman of the U.S. Joint Chiefs of Staff, recently told CNN that an Israeli attack would set the program back only “a couple of years” and “wouldn’t achieve their long-term objectives.” (Because a U.S. strike would potentially be more effective, the administration has kept that option on the table even as it has cautioned against an Israeli attack.)

Should Israel rush to war, Iran might follow Hussein’s example and rebuild its nuclear program in a way that is harder to detect and more costly to stop. And while there seems to be consensus among Iranians that the country has a right to a robust civilian nuclear program, there is no domestic agreement yet on the pursuit of nuclear weapons. Even the supreme leader has hedged his bets, insisting that Iran has the right to pursue technological advances with possible military applications, while repeatedly declaring that possession or use of nuclear weapons would be a “grave sin” against Islam.

After an Israeli strike, that internal debate would be settled — hard-line arguments would win the day.

Short of invasion and regime change — outcomes beyond Israel’s capabilities — it would be nearly impossible to prevent Iran from rebuilding its program. Iran’s nuclear infrastructure is much more advanced, dispersed and protected, and is less reliant on foreign supplies of key technology, than was the case with Iraq’s program in 1981.

Although Barak often warns that Israel must strike before Iran’s facilities are so protected that they enter a “zone of immunity” from Israeli military action, Iran would be likely to reconstitute its program in the very sites — and probably new clandestine ones — that are invulnerable to Israeli attack. An Israeli strike would also end any prospect of Iran cooperating with the IAEA, seriously undermining the international community’s ability to detect rebuilding efforts.

Barely a week after the Osirak raid, Begin told CBS News that the attack “will be a precedent for every future government in Israel.” Yet, if history repeats itself, an Israeli attack would result in a wounded adversary more determined than ever to get a nuclear bomb. And then the world would face the same terrible choices it ultimately faced with Iraq: decades of containment to stall nuclear rebuilding efforts, invasion and occupation — or acquiescence to an implacable nuclear-armed foe.