TEL AVIV - A growing cadre of former Israeli security officials are publicly faulting their government for opposing the nuclear deal negotiated in 2015 between Iran and world powers, and warning that economic sanctions on Iran are not deterring it from developing a bomb.

While Israel had applauded President Donald Trump’s withdrawal from the accord in 2018, these former officials have concluded that his “maximum pressure” policy built primarily on sanctions has failed to prevent Iran from dangerously advancing its nuclear program.

With negotiations over reviving the nuclear treaty now struggling in Vienna, Israeli Prime Minister Naftali Bennett has been echoing the ominous rhetoric of his predecessor, Benjamin Netanyahu, and accusing Iran of using “nuclear blackmail” as a bargaining tactic by escalating its uranium enrichment.

But former Israel security officials are increasingly critical of the role Netanyahu played in opposing the original agreement and urging Trump to abandon it. These officials say the accord was imperfect but that the alternative has been worse.

This approach enabled “Iran to accumulate a lot more material, work on advanced centrifuges, and maybe other things that we don’t know about, all which brought Iran closer than ever before” to acquiring a nuclear bomb, said Yoel Guzansky, former head of the Iran desk at Israel’s National Security Council and a senior fellow at the Institute for National Security Studies (INSS). “The nuclear deal was flawed, but at least it put a lid on Iran’s advancement, which we don’t have now.”

The former officials say the pact had subjected Iran to restrictions and to international inspections that held in check crucial elements of the nuclear program, while enhanced sanctions have achieved far less.

“Today, it’s clear that maximum pressure did not yield its political objectives,” said Raz Zimmt, a former military adviser on Iran. He said the policy may actually have accelerated Iranian nuclear progress and that Iran now has the capability of producing enough fissile material for a nuclear bomb on four weeks’ notice.

“It doesn’t matter how much pressure you put on them, the Iranians see their nuclear program as an insurance for the regime,” said Zimmt, who is now at the INSS, affiliated with Tel Aviv University.

When Trump pulled out of the pact, much of the Israeli public cheered. Netanyahu took credit for making it happen, and Bennett hailed it as “a great day for the free world.” Many Israelis agreed with their government that it was up to Israel to pursue an Iran policy of zero engagement, maximum economic pressure and clandestine sabotage attacks.

After 2018, Israel increasingly publicized its shadow efforts to hamper Iran’s nuclear progress. In the summer of 2020, a series of mysterious explosions took place at or near sensitive Iranian nuclear facilities. In November of last year, the country’s top nuclear scientist, Mohsen Fakhrizadeh, was ambushed and killed in an assassination near Tehran widely attributed to Israel.

But the escalation of alleged sabotage attacks has coincided with unprecedented Iranian production of highly enriched uranium. Earlier this year, Iran reached 60% uranium enrichment, approaching the 90% purity level needed for a nuclear weapon, the International Atomic Energy Agency said in August.

Maj. Gen. Amos Yadlin, the former head of Israeli military intelligence, said on Channel 12 last week that the “issue of material is maybe already behind us. Israel needs to focus on the weaponization phase,” referring to techniques for delivering and triggering a bomb.

Danny Citrinowicz, the former head of the Iran branch of Israel’s military intelligence unit, said the attacks on targets in Iran had played into the hands of that country’s hard-liners, who sought to accelerate the nuclear program.

“History has proven that the attacks were maybe a kind of tactical miracle, like James Bond movies, but they were strategic failures,” said Citrinowicz, now a senior research fellow at the Institute for Policy and Strategy in Herzliya. “Even if they delayed the nuclear program for one week or one month, then what?”

He said that Western isolation from Iran also contributed to the electoral downfall of Iranian President Hassan Rouhani, considered a pragmatist, and the victory of ultraconservative Ebrahim Raisi, a disciple of Ayatollah Ruhollah Khomeini who has long argued that Israel is a “cancerous tumor” that should be annihilated, and that the West cannot be trusted.

Israeli officials have been increasingly speaking about launching a military strike against Iran, with or without U.S. cooperation, in case negotiations fail. Most Jewish Israelis still see Iran as an existential threat and support Israeli military action - even without American consent - rather than diplomacy to resolve the crisis, according to a November poll by the Israel Democracy Institute.

Israeli Defense Minister Benny Gantz told Foreign Policy magazine in September that he would accept “the current U.S. approach of putting the Iran nuclear program back in a box,” but he added that Israel was urging the Biden administration to put military options on the table.

The Israeli military on Nov. 4 received a $1.5 billion budget allocation for a potential strike on Iran to pay for aircraft, intelligence-gathering drones and armaments, and officials in the Israel Defense Forces assert that military action has always been on the table. “We, as the IDF and Israel, are prepared to defend ourselves, by ourselves,” said a senior military official, speaking on the condition of anonymity because of the sensitivity of the matter.

But former Israeli prime minister Ehud Barak wrote on the Israeli news site Ynet that Israel can learn from experience that Iran has the ability to advance its nuclear program, even under sanctions, and that publicly breaking with the United States on Iran policy - as Netanyahu did with the Obama administration - serves no national security purpose.

“This new reality requires a sober assessment of the situation, decisions and actions and not hollow public threats - which may impress some Israeli citizens, but not the Iranians nor their negotiating partners,” he said.