This dissertation comprehensively evaluates, for the first time, nonviolence and its relationship to International Relations (IR) theory and US foreign policy along the categories of principled, strategic, and regulative nonviolence. The current debate within nonviolence studies is between principled and strategic nonviolence as relevant categories for theorizing nonviolent resistance. Principled nonviolence, while retaining the primacy of ethics, is often not practical. Indeed, most nonviolent movements have not been principled, or solely principled. Strategic nonviolence is attractive because it does not require any individual or group to believe in a particular faith or ethical tradition. However, strategic nonviolence is problematic as a source for action because it empties nonviolence of ethical content. If left with only the categories of principled and strategic nonviolence any analysis of US foreign policy is hampered by either principled nonviolence's impracticability or by the possibility that strategic nonviolence will be used for unethical ends, what I term "imperial nonviolence". This tension led me to search for a middle path between principled and strategic nonviolence. "Regulative nonviolence" is so-called because the concept owes an intellectual debt to Immanuel Kant. It is theoretically possible to argue for a US foreign policy that is grounded in the regulative ideal of nonviolence while it is nearly impossible to get from the current American policy of overwhelming force to one of principled nonviolence. In the end, regulative nonviolence is more ideal than strategic nonviolence, it retains the ethical core of principled nonviolence without removing all forms of violence from its operational tool kit. However, it is also more "realistic" than principled nonviolence because it recognizes that politics is the art of the possible. In this sense, this dissertation owes a debt not just to Kant but also to Machiavelli, with a slight twist. While Nicoló Machiavelli argued that political leaders must learn how "not to be good" I am arguing that they must learn how to be good, or, at least, to be less violent in their pursuit of political change.