until 20 May 1956, about half a year, to achieve the same results through the Cherokee nuclear weapons test. However, by this time the USAF had several hundred multi-megaton bombs in their arsenal, and more than 1,100 aircraft able to deliver them. Important results of RDS-37 The RDS-37 tests at the Semipalatink Site proved to bring the Soviet Union back into the arms race with the United States. A large part of this was due to the fact that the Soviet Union was the first nation to successfully employ the use of lithium deuterium as a thermonuclear fuel. Another important factor to consider was the accuracy with which the Soviets were able to predict the energy yields of their bombs. The predictions for the RDS-6 tests were accurate up to 30% and the RDS-37 tests were accurate to within 10%, whereas the American counterpart energy yield predictions were off by a factor of two and a half in the Castle Bravo test. The Soviets also delivered a weapon-ready design for the RDS-37. On the American side of the arms race, the bombs being tested were remotely detonated. "The test was the culmination of many years of labor, a triumph that has opened the way to the development of a whole range of devices with diverse high-performance characteristics." The report on the RDS-37, written by Zel'dovich and Sakharov, stated that the new principle of atomic compression as seen in the RDS-37 was a "shining example of creative teamwork." The report boasted enormous amounts of design-oriented, experimental and technological efforts carried out under the supervision of Design Bureau 11's chief designer, Khariton. The successful detonation of the first two-stage thermonuclear weapon was an important moment in the Soviet Union's nuclear weapons program and helped shape the path of the program. It had shown that the gap between the United States and the Soviet Union was closing. More importantly, the nuclear yield gap had been closed. It was now a race between the nations to perfect the bomb, making it lighter, reliable, and more compact. Now, 22 November 1955, marked the date where the Soviet Union possessed a weapon that could destroy any target in the United States. The thermonuclear weapons race between the United States and the Soviet Union exceeded all expectations set out before the scientists who took part. Two countries creating thermonuclear weapons with such energy yields from two different