Secretary Cohen emphasizes a point during a Pentagon press briefing on proliferation. Secretary of Defense William S. Cohen emphasizes a point during a Pentagon press briefing on Nov. 25, 1997. Cohen released the second edition of "Proliferation: Threat and Response" which discusses the worldwide threat of nuclear, chemical, and biological weapons and the Department of Defense response to counter these threats. SHARE: Download: Full Size (0.05 MB) Credit: VIRIN: 531022-M-IMN30-156.jpg Photo Gallery