Answer: B. The Pentagon was worried that the shattered remains of the Soviet Union might be rebuilt before the United States.
This line gives us the most cultural context for this excerpt as it points out to us that the events the excerpt is describing happened within the context of the Cold War. We can assess this by the mention of the Soviet Union (which ceased to exist after the Cold War) and by referring to its "shattered remains," most likely the result of World War II.