No people in history have preserved their freedom who thought that by not being strong enough to protect themselves they might prove inoffensive to their enemies.

Dean Acheson (1893-1971) American statesman

National Security Council Report 68 (NSC-68), Sec. 7 “Present Risks” (14 Apr 1950) [with Paul Nitze]
    (Source)

Usually paraphrased as "No people in history have ever survived who thought they could protect their freedom by making themselves inoffensive to their enemies."