In the mid-1940s, Argentina was partially isolated and ruled by a military regime. The political confrontation between the military and the scientific community as well as international pressures played a major role in the failure of the first attempts to cope with nuclear development. Only after the relationship between the military and local scientists was readjusted and control of atomic energy was placed in the hands of the Navy, and Argentina's international relations restored, did nuclear development begin to take off. This paper examines the traumatic process of creating the political and institutional conditions for the reception of nuclear technology in a peripheral context. The key to shaping future policies was the decision made by Argentina's Atomic Energy Commission in April 1957 to construct its first research nuclear reactor instead of buying it as other countries such as Spain and Brazil were doing at the time.