UN's nuclear probe of Iran falters

A once-promising UN attempt to probe suspicions that Tehran worked on atomic arms is faltering, and with it, hopes that Iran and six world powers can meet their July target date for an overarching nuclear deal.
With efforts to draft the text of an agreement starting in Vienna on Wednesday, both sides say that meeting the informal July 20 deadline remains possible.
The US administration gives it a 50-50 chance, and Iranian Foreign minister Mohammad Javad Zarif recently said the talks are progressing at an "unexpectedly fast pace."
The United States, Russia, China, Britain, France and Germany want to reduce Iran's present nuclear weapons-making potential. Tehran has been engaging with them over the past six months in exchange for full sanctions relief, even though it insists it has no interest in such arms.

But the UN's International Atomic Energy Agency is no nearer to closing the books on persistent allegations that Iran worked on nuclear arms in the past. While the IAEA's probe is formally separate from the talks, the US and its allies insist that Tehran must provide satisfactory explanations to the UN agency as part of any overall deal.
Back in November, Tehran agreed to go into deeper explanations of its work on detonators that have a variety of uses, including sparking a nuclear explosion.

That has not happened. Three diplomats told The Associated Press today that in a recent formal response, Iran continues to insist that there is no nuclear link to the detonators.

Tehran says they were developed only to set off conventional military blasts, and later for civilian uses.
The IAEA outlined its suspicions in a 2011 report on a wide range of suspected weapons experiments.
It said then that Iran's work on the detonators is of concern, "given their possible application in a nuclear explosive device, and the fact that there are limited civilian and conventional military applications for such technology." Signed soon after Iran's reformist government took office, the November Iran-IAEA deal as seen as important for testing Tehran's professed willingness to de-escalate tensions over its nuclear program.
The UN agency and its western members had hoped the agreement would finally mean Iran would crack open the door on what they say was secret nuclear weapons work.

But Tehran's latest response suggests it is not ready to change its stance.