The article features the role of expert approaches in decision-making concerning the military intervention in Afghanistan by the USSR and the USA. The author identified the subjects, methods, and functions of political expertise in the war in Afghanistan based on minutes of Political Bureau of the Central Committee of the Communist Party and analytical reports declassified by the Central Intelligence Agency. The Soviet authorities employed experts from those departmental structures that were inherent in the original political decision-making system. This short-term expert support was to provide a system of measures for the implementation of the state policy, i.e., the expert structures were subordinate to the government. The US authorities, on the contrary, relied on the sociological factors in their analysis of the unfolding scenario. This approach allowed them to identify which forces and entities to support at the initial stage. By establishing contacts with the religious opposition, they eventually developed weapon traffic routes. In the USSR, the faulty expert approach aggravated the inconsistency of the Soviet policy while US expert reports contributed to the outbreak of war in Afghanistan.