News of the plan requiring Iran to export 1,200 kilograms of its enriched uranium to Russia and then France in return for fuel rods for its research reactor has been greeted with thinly concealed dismay.
Defense Minister Ehud Barak became the most senior Israeli politician to attack the deal. He drew attention Thursday to the fact that the arrangement will not stop Iran continuing its own uranium enrichment.
"If you don't halt the uranium enrichment, the only remaining result is that Iran will have gained legitimacy," he told a Jerusalem conference.
He urged the west to make good on threats to impose severe sanctions on Iran if it did not stop enrichment, recommending "immediate harsh sanctions free of any illusions and with eyes wide open, while maintaining the principle...not to take any option off the table under any circumstances."
That was a clear reference to the threat of military strikes against Iran's nuclear facilities.
Israel, which has its own nuclear arsenal, has reluctantly acquiesced to American engagement with the Iranian regime in recent months, although senior figures have expressed their disapproval. At the same time the Israeli military establishment has been dropping hints about its continued preparations for the use of military force.
Some officials now fear the deal being thrashed out in Vienna this week lets Tehran off the hook.
Even the more dovish opposition leader Tzipi Livni is lining up against it.
"Israel needs to be worried by what we are witnessing today and the reports of the agreement. We suspect that this is another attempt by Iran to buy time. Israel must rally the world as this is not solely Israel's problem," she told an audience of Israeli farmers today.
Shaul Mofaz, a one time defense minister under Ariel Sharon, summed up widespread fears about what the West does not know about Iran's secretive program.
"Iran has two nuclear programs, one overt, and one secret, and the site discovered in Qom by the Americans is part of the secret plan. This agreement does not prevent them from continuing with the same plan," Mofaz said.
He added that the tentative Iranian agreement would simply be a ruse to allow it to continue its clandestine activities without supervision.
Israelis fear the agreement will only set back the Iranian program by a year or two and it is a program they are convinced is principally designed to achieve nuclear weapons. They also understand that an emerging diplomatic deal of this sort will make any plans for a unilateral attack on Iran much more difficult.