The high-profile Iranian nuclear peace offensive launched with fanfare by newly elected President Hassan Rouhani at the United Nations last month has disturbed long-standing U.S. allies in the Middle East such as Saudi Arabia and Israel. They are right to be worried.

So far, Iran continues to insist on its right to enrich uranium. Moreover, it refuses to close an enrichment facility under control of the Iranian Revolutionary Guard.

If talks are to advance, the United States and its co-negotiators from the European Union, Russia and China will have to make concessions leaving Iran with the capability to make nuclear weapons even if its immediate ambitions are blunted.

It makes you wonder why some Western diplomats were expressing “cautious optimism” following last week’s closed meeting in Geneva.

Since 2006 the United Nations has demanded that Iran stop enriching uranium, a process that produces material for nuclear weapons. Meanwhile, Iran has built up a large-scale uranium-enrichment industry.

It has manufactured a large amount of low-enriched uranium suitable to fuel a power-generating nuclear reactor, and has started accumulating medium-enriched fuel for a research reactor that makes medical isotopes used to fight cancer.

And it can make high-enriched uranium used in nuclear weapons if it so chooses.

Up until now Washington and its allies, negotiating for the U.N., have demanded that Iran give up weapons-grade uranium as a first step toward lifting sanctions.

But essentially conceding that Iran has reached a point where it can go for nuclear weapons if it wishes, a high-level administration official told The New York Times last Monday that the U.S. now only seeks to restrain the Iranian program “and perhaps take it back a notch” in order to “put some more time on the clock” before Iran achieves nuclear weapons.

Meanwhile, Russia’s representative to the Geneva talks with Iran suggested that it only remains necessary for Iran to answer some questions raised by the International Atomic Energy Agency in order to have U.N. sanctions lifted.

Iran has timed its push to get sanctions lifted with a shrewd eye on President Obama’s need for a foreign policy “success.” No wonder the Saudis are reported to view the administration as having gone soft. No wonder that the Israeli cabinet issued a statement before the Geneva meeting warning about the dangers of a premature end to sanctions if it allows Iran to continue taking steps leading to nuclear weapons.