It’s been nearly a year since a U.S. airstrike killed Maj. Gen. Qasem Soleimani, commander of the Iranian Quds Force in Baghdad. The fallout — or lack thereof — from that strike should make us cautious in assessing the impact of Friday’s killing east of Tehran of Mohsen Fakhrizadeh, a leading Iranian nuclear weapons scientist.

Hawks such as former Trump national security adviser John Bolton expressed hope in January that Soleimani’s death would force Iran to scale back its regional aggression and could even set in motion “regime change in Tehran.” Many critics of the Trump administration, on the other hand, expressed fear that his death could drag the entire region into war.

Neither prediction has panned out. Iran’s response to Soleimani’s killing was limited to a dozen missiles fired against two U.S. bases in Iraq that, whether by design or out of serendipity, killed no U.S. personnel (although they did cause a number of brain injuries). That satisfied Iran, at least for the time being, and gave both sides an off-ramp from further escalation.

But there is no evidence that Soleimani’s death set back Iran’s regional designs. Soleimani was simply replaced by his deputy, Brig. Gen. Ismail Qaani, and the Quds Force continued business as usual in Lebanon, Syria, Iraq and Yemen, where its influence is dominant. Qaani just visited Iraq to tell Iranian proxy forces to avoid any provocations while Trump is reducing the U.S. troop presence on his way out of office. That advice — “order” is more like it — has largely been heeded despite a rocket attack on the Green Zone in Baghdad last week which caused no casualties.

In short, Soleimani’s death made headlines but changed little. The same is likely to be true of Fakhrizadeh’s death, despite Tehran’s vows of revenge against the “usurper Zionist regime.” (As usual, Israel neither claims nor denies responsibility for the killing.)

President Trump was quick to retweet veteran Israeli journalist Yossi Melman’s remark that Fakhrizadeh’s death is a “a major psychological and professional blow for Iran.” But had he bothered to click on the actual article in Haaretz, he would have read Melman’s argument that “despite the blow to morale, Iran will find a nuclear scientist just as talented as the assassinated Fakhrizadeh.”

That is surely right: Fakhrizadeh’s death will not be a mortal blow to Iran’s nuclear program any more than the Manhattan Project would have ended had Robert Oppenheimer, to whom Fakhrizadeh has sometimes been compared, died during World War II. Iran’s nuclear program is a large, bureaucratic organization that can easily survive the demise of any leader.

There has been a great deal of speculation that Israeli Prime Minister Benjamin Netanyahu ordered the killing to sabotage attempts by the Biden administration to reconstitute the Obama-era nuclear deal that he loathes. “The reason for assassinating #Fakhrizadeh wasn’t to impede Iran’s war potential, it was to impede diplomacy,” tweeted a former State Department official.

Maybe so, but an earlier round of killings of Iranian nuclear scientists — four dead and one wounded between 2010 and 2012 — helped make a diplomatic solution more, not less, likely. Those killings, along with a strong international sanctions regime and U.S.-Israeli cyberattacks on Iranian nuclear facilities (most famously, the “Stuxnet” virus), added to the pressure on Iran and produced a diplomatic breakthrough for the Obama administration in 2015.

Michael Hayden, CIA director from 2006 to 2009, told the Israeli journalist Ronen Bergman “that the death of those human beings had a great impact on their nuclear program.” Hayden believed the killings hurt Iran in three ways, Bergman wrote: “the loss of the know-how in the dead men’s minds; the significant delays in the program resulting from the need to beef up measures to prevent penetration by western intelligence and the abandonments of the program by experienced experts for fear that they would suffer a similar fate.”

It will be an ironic twist of fate if Fakhrizadeh’s death only adds to the pressure on Iran to conclude a deal with a Biden administration staffed by many of the same officials who negotiated the earlier agreement. That might be the last thing that Netanyahu or Trump wants, but a diplomatic breakthrough is necessary to stop the Iranian nuclear program.

If recent history has taught us anything, it is that Iran can keep developing nuclear weapons no matter how many of its scientists are killed by assassins, how many of its centrifuges are felled by cyberattacks, or how much of its economy is damaged by sanctions. Since Trump foolishly pulled out of the nuclear deal in 2018 despite Tehran’s compliance, Iran has increased its uranium stockpile eightfold. Even airstrikes would not eradicate the Iranian program while risking a regional conflagration.

The only way to stop the Iranian nuclear program is through a new nuclear deal. For the sake of Israel, the United States and the entire world, let us hope that Fakhrizadeh’s death makes a diplomatic breakthrough more, not less, likely.

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