Science and technology influence international affairs by many different mechanisms. Both create new issues, risks and uncertainties. Advances in science alert the international community to new issues and risks. New technological capabilities transform war, diplomacy, commerce, intelligence, and investment. This paper identifies six basic patterns by which advances in science and technology influence international relations: (1) as a juggernaut or escaped genie with rapid and wide-ranging ramifications for the international system; (2) as a game-changer and a conveyer of advantage and disadvantage to different actors in the international system; (3) as a source of risks, issues and problems that must be addressed and managed by the international community; (4) as key dimensions or enablers of international macro phenomena; (5) as instruments of foreign policy or sources of technical information for the management of an ongoing international regime; (6) as the subject of projects and institutions whose planning, design, implementation and management provide grist for the mill of international relations and diplomacy.