DONALD G. BRENNAN is a mathematician and a student of national security affairs. From July 1962 to May 1964 he served as the president of Hudson Institute. His special interests are in advanced military policy, European alliance relationships, and selected areas of arms control. Formerly, he spent nine years as a research mathematician and communication theorist at Lincoln Lab, MIT, where he devoted substantial time also to studies of arms control and national security policy problems. In 1957 he organized a group that led to the 1958 Summer Study on Arms Control held in Cambridge under the auspices of the American Academy of Arts and Sciences; he was the organizer and co-director of a similar study at Cambridge in 1960. He was also a consultant to the Department of State, DoD, Arms Control and Disarmament Agency, and the Executive Offices of the President. A member of AAAS's Committee on International Studies of Arms Control, he served as its chairman in 1961-62. Dr. Brennan edited the anthology, *Arms Control, Disarmament, and National Security*, sponsored by AAAS, served as guest editor of the special (Fall 1960) issue of *Daedalus* on "Arms Control" and has lectured on national security subjects at Harvard, MIT, the University of California, and at defense study centers in Bonn, Paris, and Oslo, among others. He was a member of the President's National Citizens' Commission on International Cooperation Year in 1965. B.S., 1955 and Ph.D., 1959 in Mathematics, MIT.