Fasten your seat belts, it’s going to be a bumpy ride. Donald Trump, who will be sworn in as the 45th president of the United States on Friday, seems set to transform the global agenda, as well as the style in which decisions are made and implemented in Washington. When Trump promises the American people an “unpresidented” presidency, we have to believe him — even if the term or two he spends in office develop in unanticipated directions.

During his election campaign, Trump promised that after he takes office he will tear up the Vienna agreement on limiting Iran’s nuclear program that Tehran signed with the six powers in July 2015. Prime Minister Benjamin Netanyahu said on CBS’ “60 Minutes” last month that he has “at least five ideas in mind” for how Trump could undo the agreement and that he would reveal them when the two meet. Netanyahu is expected to be one of the first foreign leaders to meet with the new president.

Some figures in Israel’s defense establishment think differently. According to one intelligence assessment that was presented to Netanyahu recently, a U.S. decision to revoke the Vienna agreement could be a serious error.

Israeli intelligence organizations had a lot of criticism for what they saw as gaps and errors in the agreement when it was signed, but in the year and a half since then they seem to have concluded that it is quite stable and that Iran is in compliance with it, over all.

There is concern that revoking the pact would cause a chasm between Washington and the other signatories, most importantly Moscow and Beijing. In addition, a direct clash between Iran and the United States over the issue would mean forfeiting the agreement’s accomplishments: Iran’s commitment to refrain from creating nuclear atomic weapons, setting back its project by at least several years and extending the “breakout time” Tehran would need in order to produce a single nuclear weapon.

The heads of Israel’s army and other defense organizations have not spoken publicly about the possibility of revoking the agreement. Both it and any speculation about the Trump presidency are off limits even for background briefings with journalists. But former chiefs of Military Intelligence are free of such constraints, and two of them — Amos Yadlin and Aharon Ze’evi-Farkash — spoke with Haaretz this week. Both men believe Israel must take care not to spur Trump into revoking the agreement with Iran.

Yadlin, the executive director of Tel Aviv University’s Institute for National Security Studies (which holds its annual conference next week), says that Netanyahu has a rare opportunity to rectify the mistake he made in 2015 after the agreement was approved.

“Instead of fighting the agreement in Congress, the prime minister should have arrived at understandings with the Obama administration: He should have agreed to tighter security coordination, to tracking the Iranian moves jointly and to coordinating in secret the manner of response should it be discovered that they were violating the agreement,” Yadlin said, adding: “At that time there was also a missed opportunity to receive from the Americans security aid,” much more generous than the $38 billion over the next 10 years that President Barack Obama announced in September.

Open gallery view Amos Yadlin Credit: Alon Ron

According to Yadlin, it is precisely because he did not sign the agreement that Trump will be able to take a tougher approach to Iran without undoing the pact.

“It is possible to persuade the incoming president to act to curb Iran’s activity in the production of ballistic missiles, its regional subversion and its aid to terror organizations. But precisely the act of cancelling the agreement will negate the legitimacy of our positions in the international community. When a conflict with Iran develops, the other powers will blame us for dragging Trump into doing this. They will not come to our aid,” Yadlin said.

Ze’evi-Farkash agrees with his successor that Iran’s missile testing opens it up to pressure. At the same time, he says, Netanyahu has to propose to Trump that he recruit Congress to his side, by approving the decision authorizing the president to take any measures necessary in the event the agreement is violated. “There is no reason to cancel the agreement now,” Ze’evi-Farkash says, “despite its flaws. The correct alternative lies in a coordinated American–Israeli move that will also prepare to deal with Iranian violations during the period of the agreement and also with the gradual lifting of the restrictions on Tehran, nine years from now.”