J. Daniel Howard Carlucci and his deputy, General Colin Powell. Howard focussed on arms control issues and remained through the signing of the Intermediate-Range Nuclear Forces Treaty in January 1988. He also dealt with many issues associated with the Iran–Contra affair. On December 21, 1987, President Reagan nominated Howard to serve as Assistant Secretary of Defense (Public Affairs) and Howard would hold this post from February 1988 through May 1989. He worked for Secretary of Defense Frank Carlucci and dealt with the aftermath of the shooting down of Iran Air Flight 655 by the U.S.S. "Vincennes" and the explosion of a gun mount
United States Secretary of Defense 2,595 days. Combining his two non-sequential services as Secretary of Defense, the second longest serving is Donald Rumsfeld, who served just ten days fewer than McNamara. The shortest-serving Secretary of Defense is Elliot Richardson, who was quickly moved to US Attorney General after 114 days due to resignations during the Watergate Scandal (not counting Deputy Secretary of Defense William P. Clements and William Howard Taft IV, who each served a few weeks as temporary/acting Secretary of Defense). The Secretary of Defense is sixth in the presidential line of succession, following the Secretary of the Treasury and preceding the Attorney General.