Russian interference with the 2016 U.S. elections brought the problem of foreign influence on American politics into sharp relief. However, externally-sponsored subversion of U.S. decision making has been a shadowy threat to American policy for the better part of a century. Political Influence Operations provides an incisive examination of how external actors have infiltrated American society?from lobbyists, to academia, to the media?in order to further their own objectives. Tromblay draws upon historical examples to demonstrate how U.S. adversaries ? and sometimes its ostensible allies ? have used the openness of American society against the country?s best interests. By identifying vulnerabilities and exposing the underlying dynamics of foreign influence, the book provides a roadmap for U.S. governmental and private sector entities to navigate the currents of international engagement.