The former Mossad chief Efraim Halevy, who told The Times of Israel in an interview in March that there would be “nothing else left” but a resort to force if the diplomatic track with Iran did not quickly produce a breakthrough, hinted Thursday that the moment of truth on Iran’s nuclear drive was now imminent.

“If I were an Iranian, I would be very fearful of the next 12 weeks,” Halevy, who is also a former national security adviser and ambassador, told The New York Times.

In an Israel Radio interview later Thursday, he added that Israel’s threats of military action had a certain “credibility” and “seriousness.” He said the Iranian nuclear issue, and the Syrian issue, were the key regional concerns, and reiterated that “If I were an Iranian, I would be very fearful of the next 12 weeks.”

The New York Times report, focusing on Wednesday’s talks here by Defense Secretary Leon Panetta, said there was “feverish speculation” in Israel that Prime Minister Benjamin Netanyahu “will act in September or early October.”

Apart from Netanyahu’s concern that Israel’s military option would “soon” become redundant, the paper cited several other reasons “for the potential timing.” Among them, it said, was the fact that “Israel does not like to fight wars in winter.” Also, Netanyahu “feels that he will have less leverage if President Obama is reelected” while, were Mitt Romney to win the November elections, “the new president would be unlikely to want to take on a big military action early in his term.”

Still, Thursday’s article continued, “a number of administration officials say they remain hopeful that Israel has no imminent plans to attack and may be willing to let the United States take the lead in any future military strike, which they say would not occur until next year at the earliest.”

The New York Times further reported that administration officials say “Israeli officials are less confrontational in private” and that Netanyahu “understands the consequences of military action for Israel, the United States and the region. They say they know he has to maintain the credibility of his threat to keep up pressure on the United States to continue with sanctions and the development of military plans.”

In his interview with The Times of Israel in late March, Halevy said that if the then-upcoming international talks with Iran on thwarting its nuclear program did not quickly produce a breakthrough, there will be “nothing else left” but a resort to force.

He also said he had “no doubt that for the past few years Israel has been readying its capabilities to meet the Iranians if necessary by force.

It was “tragic,” Halevy added at the time, that “I don’t see any great effort being made” by the P5+1 group — the five UN Security Council permanent members and Germany — to prepare urgently and effectively for those talks. The lights “should be burning through the night” to get a strategy together, he said. “The number one thing the world should be doing [on Iran] is investing enormous preparation into the P5+1 confrontation, because this is really the ‘Last Train to San Fernando.’”

Iran, he predicted, would doubtless try to play for time in the talks. The international community, therefore, needed to be ready with its strategy and tactics, and to be represented by “a very high-level, experienced, wise and creative negotiator.”

For the international community, said Halevy, “there’s no time for, you know, ‘Let’s meet again in two or three months, let’s do our homework, let’s not rush things, let’s look at it, and so forth.’” Rather, he said, “there has to be a breakthrough… If there is no breakthrough, it means to say that the talks have failed.”

Asked if, by a breakthrough, he meant Iran announcing the suspension of its nuclear program, Halevy demurred. “I don’t want to say ‘Iran suspending the program.’ I don’t believe that everything will become public overnight.” But it would need to be clear, he said, “that there is a serious negotiation… They don’t have to spell it all out, but it has to be clear.”

Halevy said he did see signs of greater potential international coordination over Iran. He was encouraged by the growing consensus on tackling Syria, notably including Russia and China, which he said could also be reflected in a coordinated strategy on Iran. He also noted that the priority for the ayatollahs’ regime in Iran is “survival” at all costs.

Nonetheless, if the negotiations fail, “there’s nothing else left” but a resort to force, he said.

Perhaps, it was put to Halevy, Israel could live with a nuclear weapons-capable Iran? Halevy responded: “I don’t think that we should countenance that as long as we can do what we can to remove it. I don’t accept the notion that Israel is destructible. But I think that if Iran retains a nuclear capability, life here is going to be very tough for a very long period to come. Israel will not disappear, but Israel will go through a period which I would not like it to go through.”

Asked whether he believed the Israeli government wanted a diplomatic solution, he answered: “I’m not sure every Israeli wants a diplomatic solution… I’m not sure that the government is entirely behind this support for a diplomatic solution.”