Caldwell is an expert on Soviet and post-Soviet foreign and military policies, arms control, and U.S. national security policy. He joined Occidental in 1967.
He has served as research associate at the International Institute of Strategic Studies in London; as a visiting professor and director of European studies at the National War College in Washington; as a scholar-in-residence in the Office of Soviet Analysis at the CIA; and as a staff member and consultant at the Jet Propulsion Laboratory and the Rand Corporation. He has held Ford, Rockefeller, and NATO research grants, testified before Senate and House committees, and advised congressional and presidential campaigns. He wrote Soviet and American Attitudes Towards S.A.L.T. (1971), Soviet and American Relations: One Half-Decade of Detente (1976), and U.S.-Soviet Relations in the 1980s with William Diebold, Jr. (1980).