With the election of President Richard M. Nixon in 1968 and the announcement of the new American policy of Vietnamization in 1969, America's relations with Cambodia began to change. The goal of the U.S. was now to buy time for their South Vietnamese allies (and to cover their own withdrawal). On 11 May 1969 Sihanouk welcomed a return to full diplomatic relations with the U.S. On 18 March Nixon, already anticipating this development, ordered the bombing of the Cambodian sanctuaries by B-52s. On that date 48 bombers, under secret orders from the president, crossed into Cambodian airspace and delivered their payloads in Operation "Breakfast". During the next 14 months this operation was followed by "Lunch", "Snack", "Dinner", "Dessert", and "Supper" as American bombers flew 3,630 sorties and expended 100,000 tons of ordnance on the Base Areas in what came to be called Operation Menu. During this time frame, the entire program was held as a closely guarded secret from Congress, the American people, and amazingly, from the Air Force itself.