By the late 1950s, the Soviet Union had acquired a strong position as a world oil exporter, thanks to major discoveries in the Ural-Volga area. In order to transport their oil to strategic areas within the Union and to Europe, the Soviets devised a project to build a colossal pipeline system. This plan caused anxiety at NATO since Russian oil could be wielded as a weapon to weaken the West both militarily and economically. In order to complete the system, however, the Soviets needed large-diameter steel pipes and equipment, which they had to import from the West. Thus in 1961 the U.S. delegation at NATO proposed a comprehensive embargo of large-diameter pipes in order to delay the system’s construction. I argue that the definition of what oil pipes were as technological artifacts, as well as their final content, was ultimately shaped by the NATO debate on this U.S. proposition.