Public opinion and the politics of United States foreign policy

Over the course of the last fifty years, one of the most dominating influences on presidential decision-making has become public opinion. The public, through expressed opinion on a range of issues and through its support or lack of support for a president, has become central to presidential decision-making in both domestic and foreign policy.; This study seeks to understand the nature of the public's role in influencing foreign policy by considering the role of public opinion and the president's popularity in decisions to intervene. Two contradictory explanations for the relationship frame the study: Political capital arguments suggest that presidents are more likely to intervene when their popularity and political capital is high, and less likely to intervene when popularity is low and their political capital diminished. Rally arguments suggest that presidents are more likely to intervene when their need for increased popular support is greatest--when popularity is very low or falling, and during election periods.; To examine this relationship, a quantitative comparison of intervention actions and popularity ratings, and an in depth case study of intervention decision-making under two presidents, Jimmy Carter and Ronald Reagan, was conducted.; The study did not find a direct relationship between levels of popularity and intervention activity along the lines suggested by either rally or political capital explanations, primarily the result of a lack of evidence of direct political calculation in the decision-making process.; The impact of public opinion on foreign policy, however, was found to be substantial, pervasive, and significant. Public opinion in the form of popularity levels acts as a definer of presidential power and as a barometer of public support for a particular policy. As such, it conditions the president's ability to influence the decisions and actions of Congress, the bureaucracy, and other world leaders. Public support for or opposition to specific policy options, and the public's willingness to stand behind the president in a crisis define the boundaries of decision options, oftentimes so limiting the number of acceptable options that decisions appear almost preordained.