180209-N-ND254-004 BANGOR, Wash. (Feb. 9, 2018) Cmdr. Jeffery Yackeren, commanding officer of the Ohio-class ballistic missile submarine USS Alabama (SSBN 731) gives a tour to Deputy Secretary of Defense Patrick M. Shanahan, left. Shanahan also visited Commander, Submarine Group 9 and other facilities onboard Naval Base Kistap-Bangor, Washington highlighting the strategic deterrence mission. Alabama is one of eight ballistic-missile submarines stationed at the base, providing the most survivable leg of the strategic deterrence triad for the United States. (U.S. Navy photo by Mass Communication Specialist 2nd Class Nancy C. diBenedetto/Released)