[246]
In 1963 the Kennedy administration was engaged in a now-declassified diplomatic standoff with the leaders of Israel.[247][248] In a May 1963 letter to Ben-Gurion, Kennedy wrote that he was skeptical and stated that American support to Israel could be in jeopardy if reliable information on the Israeli nuclear program was not forthcoming, Ben-Gurion repeated previous reassurances that Dimona was being developed for peaceful purposes. The Israeli government resisted American pressure to open its nuclear facilities to International Atomic Energy Agency (IAEA) inspections. In 1962 the US and Israeli governments had agreed to an annual inspection regime. A science attaché at the embassy in Tel Aviv concluded that parts of the Dimona facility had been shut down temporarily to mislead American scientists when they visited.[249]
According to Seymour Hersh, the Israelis set up false control rooms to show the Americans. Israeli lobbyist Abe Feinberg stated: "It was part of my job to tip them off that Kennedy was insisting on [an inspection].