 Complete the following phrase:  As the Abrams entered service in the 1980s, they would operate alongside M60A3 within the United States military, and with other NATO tanks in numerous Cold War exercises. These exercises usually took place in Western Europe, especially West Germany, but also in some other countries like South Korea. During such training, Abrams crews honed their skills for use against the men and equipment of the Soviet Union. However, by 1991 the 