“Iran is continually working to rebuild its nuclear program," the former official said, speaking anonymously due to what the outlet described as pressure from Iran.
"The dialogue with the IAEA (International Atomic Energy Agency) has been interrupted, and the one with the United States is stalled and making no progress. Given this situation, there is reason to believe that we could soon find ourselves facing another round of direct war between Iran and Israel,” he added.
Israel launched a surprise military campaign in June which was capped with US attacks on the three key nuclear sites in Esfahan, Natanz and Fordow.
US President Donald Trump said the attacks had "obliterated" Iran's nuclear program but a diplomatic standoff over its fate continues to fester.
The ex-Mossad official said strikes on Iranian nuclear facilities during the twelve-day war in June caused “serious damage” but did not destroy Iran’s nuclear material, adding that Tehran is strengthening defenses around key sites.
Iran’s leadership, the former official assessed, is divided over talks with the United States, with President Masoud Pezeshkian favoring compromise while Supreme Leader Ali Khamenei and the Revolutionary Guards oppose concessions.
"I do not believe the Supreme Leader will allow Pezeshkian to reach an agreement and prevent a war. The situation could deteriorate,” he said.
Iran signals military readiness
His assessment came as Iran’s defense minister issued a fresh warning about the country’s military posture towards any hostile action from its adversaries.
Defense Minister Aziz Nasirzadeh said Iran is “monitoring threats accurately and continuously” and is prepared to respond “more decisively and more harshly than in the past."
"In the twelve-day war, we displayed part of our capabilities, and of course we did not reveal all our defensive power," he said.
"Today, with full strength and complete intelligence oversight, we are ready to respond to any threat ... If our enemies make a miscalculation and any movement or hostile action ... they will undoubtedly face an immediate and regret-inducing reaction," he added.
Mossad operates 'inside' Iran
The former Mossad official's comments followed separate disclosures about Israeli intelligence activity in Iran.
In a separate report on Thursday, Israeli newspaper Haaretz said former Mossad director Yossi Cohen told a private conference that the agency operates “inside Iran itself” and recruits sources directly, according to recordings obtained by the paper.
“(Iran) is not a place where we operate by proxy,” Cohen was quoted as saying.
“We go in to recruit and to bring intelligence,” he added.
Israeli assassinations of Iranian nuclear scientists and hundreds of military personnel and civilians during the June war exposed deep intelligence lapses in the Islamic Republic.
In the aftermath of the 12-day war which culminated in US airstrikes on three Iranian nuclear facilities, Tehran's intelligence forces arrested more than 700 Iranians accused of acting as agents for Israel.
The arrests targeted what authorities described as an “active espionage and sabotage network” that intensified operations after Israeli attacks.