Pakistan supported the United States, while India supported the Soviet Union during

a.

the Vietnam War.

c.

the Cold War.

b.

the Korean War.

d.

World War II.

The conflict in which the two powers faced each other was the Cold War (but Vietnam and Korean War were part of this. However, India and Pakistan did not participate in Vietnam or Korea Wars). So US and Soviet Union faced each other in the Cold war and Pakistan supported the United States, while India supported the Soviet Union.