wills over Israel's nuclear program. The tensions were invisible to the publics of both countries, and only a few senior officials, on both sides, were aware of the severity of the situation. According to Yuval Ne'eman, Eshkol, Ben-Gurion's successor, and his associates saw Kennedy as presenting Israel with a real ultimatum. According to Ne’eman, the former Israel Air Force commander Maj. Gen. (res.) Dan Tolkowsky, seriously entertained the fear that Kennedy might send U.S. airborne troops to Dimona, the home of Israel's nuclear complex. On March 25, 1963, President Kennedy and CIA Director John A. McCone discussed the Israeli nuclear program. According to McCone, Kennedy raised the "question of Israel acquiring nuclear capability," and McCone provided Kennedy with Kent's estimate of the anticipated negative consequences of Israeli nuclearization. According to McCone, Kennedy then instructed National Security Adviser McGeorge Bundy to guide Secretary of State Dean Rusk, in collaboration with the CIA director and the AEC chairman, to submit a proposal "as to how some form of international or bilateral U.S. safeguards could be instituted to protect against the contingency mentioned." That also meant that the "next informal inspection of the Israeli reactor complex [must] ...be undertaken promptly and... be as thorough as possible." This presidential request was translated into diplomatic action, on April 2, 1963, Ambassador Barbour met Prime Minister Ben-Gurion and presented the American request for his "assent to semi-annual visits to Dimona perhaps in May and November, with full access to all parts and instruments in the facility, by qualified U.S. scientists." Ben-Gurion, apparently taken by surprise, responded by saying the issue would have to be postponed until after Passover, which that year ended on April 15. To highlight the point further, two days later, Assistant Secretary Talbot summoned Israeli Ambassador Harman to the State Department and presented him with a diplomatic démarche on the inspections. This message to Ben-Gurion was the first salvo in what would become "the toughest American-Israeli confrontation over the Israeli nuclear program". On April 26, 1963, more than three weeks after the original U.S. demand concerning Dimona, Ben-Gurion responded to Kennedy with a seven-page letter that focused on broad issues of Israeli security and regional stability. Claiming that Israel faced an unprecedented threat, Ben-Gurion invoked the specter of "another Holocaust," and insisted that Israel's security should be protected by joint external security guarantees, to be extended by the U.S. and the Soviet Union.