Turkey has been one of NATO's best allies and has a formidable army (currently considered 13th in the world). And considering it joined in 1952 it should be very obvious why it joined at the time.
NATO looked a lot different in 1952 (especially considering this was in the middle of the Korean War), and so did the Soviet Union. NATO states who initially signed on was basically all neighbouring Warsaw Pact states or the USSR itself.
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