Read the following passage carefully and answer the following questions:
During the Cold War years, India found itself on the opposite side of the divide from the US. India's closest friendship during those years was with the Soviet Union. After the collapse of Soviet Union, India suddenly found itself friendless in an increasingly hostile international environment. However, these were also the years when India decided to liberalise its economy and integrate it with the global economy. This policy and India's impressive economic growth rate made the country an attractive economic partner for a number of countries including the US.
Name the country which was India's closest friend during Cold War years.

Explanation

Soviet Union