The revisionists have had varying impacts on how historians understand the conduct of American foreign relations in the twentieth century and on the contemporary debate over the nation's role in the world. The World War I revisionists, for example, helped create a climate that moved many in Congress and the public to support the Neutrality Acts of 1935–1937 and that impelled President Roosevelt to move cautiously during the period 1939–1941 when seeking to reorient U.S. foreign policy. The Right revisionists provided the intellectual foundation for the McCarthyite charges of the early 1950s: the need to purge subversives from the federal bureaucracy, to repudiate the Yalta Conference agreements, and to restrict presidential foreign policy authority. Sharing this framework, Vietnam revisionists provided the intellectual rationale for the Committee on the Present Danger and the Reagan administration's military and foreign policy decisions of the 1980s—whether missile defense or aid to the contras in Nicaragua. In contrast, Left revisionists influenced the debate over the Vietnam War and the containment policy during the 1960s and 1970s. Finally, the national security revisionists have both tapped into and influenced the post-1975 debate over presidential power, the role of the intelligence agencies, and secrecy policy.
The long-term impact of revisionism on the public's understanding of American foreign relations, nonetheless, has been transitory, determined by the public's changing mood and priorities. The impact of revisionists on the scholarly community has been equally transitory, depending more on the quality of their scholarship than on the questions they have posed and the insights they have offered. Their most significant contribution has been to introduce new research issues and to lend support for the release of classified reports.