Step 1: Understand NATO's purpose.
NATO (North Atlantic Treaty Organization) was created in 1949 primarily to counter the expansionist policies of the Soviet Union during the Cold War. It aimed to provide collective security against the threat of Soviet aggression in Europe.
Step 2: Conclusion.
The correct answer is that NATO was created to protect European nations from the expansionist policy of Soviet Russia.
Final Answer:
\[
\boxed{ \; protect \; European \; nations \; from \; the \; expansionist \; policy \; of \; Soviet \; Russia.}
\]