Final answer:
Vladimir Lenin enacted the New Economic Policy (NEP) as the leader of the Soviet Union. The NEP aimed to revive the Soviet economy after years of war and economic crisis.
Step-by-step explanation:
The policy enacted by Vladimir Lenin as the leader of the Soviet Union was the New Economic Policy (NEP).
The New Economic Policy was implemented in 1921 and aimed to revive the Soviet economy after years of war and economic crisis.
It introduced limited market exchange of goods and allowed small-scale private enterprise, while the state still maintained control over key industries. The NEP led to a temporary improvement in living standards and a cultural renaissance in the arts and literature.