Some argue the Iran-Contra investigations were inadequate, and that Congress shirked its constitutional responsibilities to expose the affair. Others charge Congress expects ''another Watergate'' in every partisan controversy. Neither claim establishes realistic expectations for congressional foreign policy investigations. This argument establishes a comparative framework for evaluating important Cold War investigations. Three primary dimensions shape their nature, scope, and outcome. Periods of ''emergency'' or stability in the international system affect Congress's likely deference to the president. The institutional division of foreign policy powers has cumulatively favored the expansion of presidential power during the Cold War, and formidable presidential advantages limit congressional investigations. Political culture tugs in conflicting directions. American ''exceptionalism'' promotes the expansion of presidential power, while liberal concerns for limiting state power are expressed in efforts to reassert Congress's foreign policy role. Because congressional assertiveness is a variable phenomenon, the nature, scope, and purpose of its investigations will differ in each case.