A Western diplomat who asked not to be named because he was not authorized to discuss intelligence information said the United States, Britain, France, Germany and Israel agree on that assessment.

According to the source, this assessment began to take shape in February, when Iran refused to allow inspectors from the International Atomic Energy Agency to visit the base at Parchin, where it is believed Iran is carrying out part of the research and development of its military nuclear program. Visits of IAEA inspectors in Iran, and especially revelations of information the Iranians had been trying to hide, intensified suspicions that Tehran was developing nuclear weapons at a faster pace than it had previously seemed…

An American think tank called the Institute for Science and International Security released a satellite photo of the Parchin base showing, according to Western intelligence, that Iran is developing nuclear weapons there. Taken on July 25 and released on August 1, the picture shows that the Iranians have completed what the American think tank called “cleanup” of the site where the base was.

Netanyahu told U.S. Republican presidential candidate Mitt Romney that an Israeli or American military attack on Iran’s nuclear facilities was likely to help topple the ayatollah regime, just as the 1976 Entebbe raid led to the defeat of Ugandan dictator Idi Amin, according to a senior Israeli official.