Israeli spies penetrated the heart of Iran's nuclear program and missile project years before Operation 'With Lions,' gathering intelligence covertly - which led to the assessment that Iran's weapons industry was much more advanced than previously estimated. This information comes from leaked intelligence documents obtained by the British Times, after being viewed by Western sources. According to the documents, the Mossad and Israeli Military Intelligence concluded that the knowledge and components possessed by the Iranian regime are far more advanced than the activities at sites in Fordow, Natanz and Isfahan. An intelligence source told the Times that Israel "monitored several sites from the ground for years using intelligence agents."