Eisenhower sent Kistiakowsky to Strategic Air Command headquarters where he was, at first, rebuffed. At the same time as the early nuclear arms control work, the Chairman of the Joint Chiefs of Staff, General Nathan F. Twining, USAF, sent a memorandum in August 1959, to the Secretary of Defense, Neil McElroy, which suggested that the Strategic Air Command be formally assigned responsibility to prepare the national nuclear target list, and a single plan for nuclear operations. Up to that point, the Army, Navy, and Air Force had done their own target planning. That had led to individual targets being multiply targeted by the different services. The separate service plans were not mutually supporting, as, for example, by the Navy destroying an air defense facility on the route of an Air Force bomber going to a target deeper inland. While Twining had sent the memo to McElroy, the members of the Joint Chiefs of Staff disagreed on the policy during early 1960. Thomas Gates, who succeeded McElroy, asked President Dwight D. Eisenhower to decide the policy.