Task: Explanation
Input (English): William Sebastian Cohen (born August 28, 1940) is an American politician and author from the U.S. state of Maine. A Republican, Cohen served as both a member of the United States House of Representatives and Senate, and as Secretary of Defense (1997–2001) under Democratic President Bill Clinton. Question: Under what president did William Cohen serve as Secretary of Defense in the years following the death of Esequiel Hernández Jr.? Answer: Bill Clinton
Output (English):  A Republican, Cohen served as both a member of the United States House of Representatives and Senate, and as Secretary of Defense 1997–2001 under Democratic President Bill Clinton.