to withdraw or destroy the weapons in Cuba, provided the United States would lift the blockade and promise not to invade the island. The increasing tempo in the military, however, continued unabated. SAC ordered over sixty B-52 bombers to continue on airborne alert, while TAC forces in Florida assumed a one-hour alert and prepared to go to a fifteen-minute alert, which involved pilots waiting in aircraft for launch orders. After a heated debate Robert Kennedy met with the Soviet Ambassador to the United States, Anatoly Dobrynin, and in effect, promised to remove obsolete American PGM-19 Jupiter MRBMs from Turkey. This promise was sufficient and the next day the Soviet Union informed the United States that the missiles in Cuba would be withdrawn. The Soviets began turning their ships around, packing up the missiles in Cuba, and dismantling the launch pads. As the work progressed, the Air Force started to redeploy aircraft back to home bases and lower the alert status. The United States and Soviet Union stepped back from the brink, and the crisis was resolved without armed conflict. Never in the history of the Cold War had the United States and the Soviet Union come so very close to mutual nuclear destruction. New Aircraft In 1962, the Air Force commenced evaluation of the US Navy/US Marine Corps F-4 Phantom II as a possible replacement for older fighter aircraft in the counter-air, interdiction and close air support (CAS) roles. In January 1962, two Navy F4H-1 aircraft were loaned to USAF and, since the 18 September 1962 naming convention for all DoD aircraft had not yet taken effect, were given the interim designation of F-110A Spectre. Twenty-four additional USN F4H-1 aircraft, subsequently redesignated as F-4Bs, were loaned to USAF for additional evaluation. This evaluation resulted in a USAF decision to acquire their own version of the F-4, designated as the F-4C. Following its initial flight in May 1963, the F-4C entered USAF service with TAC in November 1963. The F-4 would prove to be one of the most numerous jet fighters ever operated by USAF, with over 2800 examples acquired for service in TAC, USAFE, PACAF and the Air Force Systems Command (AFSC), to include later versions such as the RF-4C, F-4D, F-4E and F-4G. In 1960, DoD also combined a USAF requirement for a new fighter-bomber to ostensibly replace TAC's F-105 fighter-bombers with a USN need for a new carrier-based