Foreign policy of the United States is a complex mechanism defined both by constitutional law as well as by various instruments of public and private pressure. This book examines first of all the foreign policy roles of the President and Congress. History has shown control of foreign policy has shifted between the Executive Branch and Congress depending on public opinion, perceived strengths of various presidents, congressional interest levels and willingness of power congressmen to oppose the president. National interest as a foreign policy element is considered as well. Albeit a vague term that can and often is construed to mean whatever a particular president or congress is interested in the moment, there are several areas of general agreement; cheap oil for American consumers; halting nuclear proliferation; containment of Russia; following Israeli direction on Mid-East policy; trying to open Chinese markets for American companies; generally serving as an active agent of American business in global markets; maintaining and projecting American's military muscle throughout the world. The book also examines the government organisations involved in foreign policy, the laws related to various countries, foreign election monitoring, economic sanctions as instruments of foreign policy, international terrorism and the War Powers Resolution.