Unilateralism is any doctrine or agenda that supports one-sided action. Such action may be in disregard for other parties, or as an expression of a commitment toward a direction which other parties may find agreeable. Unilateralism is a neologism which is already in common use; it was coined to be an antonym for multilateralism, which is the doctrine which asserts the benefits of participation from as many parties as possible.
The two terms together can refer to differences in foreign policy approached to international problems. When agreement by multiple parties is absolutely required—for example, in the context of international trade policies—bilateral agreements (involving two participants at a time) are usually preferred by proponents of unilateralism.
Unilateralism may be preferred in those instances when it's assumed to be the most efficient, i.e., in issues that can be solved without cooperation. However, a government may also have a principal preference for unilateralism or multilateralism, and, for instance, strive to avoid policies that cannot be realized unilaterally or alternatively to champion multilateral solutions to problems that could well have been solved unilaterally.
Typically, governments may argue that their ultimate or middle-term goals are served by a strengthening of multilateral schemes and institutions, as was many times the case during the period of the Concert of Europe.
Unilateralism has had a long history in the United States. In his famous and influential Farewell Address, George Washington warned that the United States should "steer clear of permanent alliances with any portion of the foreign world". Many years later, this approach was labeled (by its opponents) as "isolationism", but some historians of U.S. diplomacy have long argued that "isolationism" is a misnomer, and that U.S. foreign policy, beginning with Washington, has traditionally been driven by unilateralism. Recent works that have made this argument include Walter A. McDougall's Promised Land, Crusader State (1997), John Lewis Gaddis's Surprise, Security, and the American Experience (2004), and Bradley F. Podliska's Acting Alone (2010).
Debates about unilateralism came up with the Iraq War. While over 30 countries have supported the U.S. policy, some previous American allies, such as France, Germany and Turkey, were not participating. Many opponents of the war have argued that the United States was "going in alone" in Iraq without the support of multilateral institutions—in this case NATO and the United Nations.
Advocates of U.S. unilateralism argue that other countries should not have "veto power" over matters of U.S. national security. Presidential Candidate John Kerry received heavy political heat after saying, during a presidential debate, that American national security actions must pass a "global test". This was interpreted by Kerry opponents as a proposal to submit U.S. foreign policy to approval by other countries. Proponents of U.S. unilateralism generally believe that a multilateral institution, such as the United Nations, is morally suspect because, they argue, it treats non-democratic, and even despotic, regimes as being as legitimate as democratic countries. Proponents also point out that the unilateralist policy of having the United States control Japan after World War II was more of a success than multilateral policies such as those used in post-war Germany. Japan took only 5 years before adopting its constitution while Germany was divided into West Germany and East Germany for 45 years and was controlled by the United States, France, Great Britain, and the Soviet Union before being reunited, although Japan, unlike Germany, was not center-stage during the early stages of the Cold War.
Critics of American unilateralism point to the ethical implications of engaging in armed conflicts that may inevitably draw in combatants from other nations, as well as the undermining of the international ability to protect small nations from aggressors. Unilateralism, it is argued, can be considered nothing more than a positively sold version of the very actions that would earn other states the title of aggressor or rogue nation. Opponents of unilateralism say it rejects the essential interwoven nature of modern global politics and perhaps underestimates the extent to which a conflict in one country can affect civilians in others.
Proponents of multilateralism argue that it would provide a country with greater resources, both militarily and economically, and would help in defraying the cost of military action. However, with divided responsibility inevitably comes divided authority, and thus (in theory at least) slower military reaction times and the demand that troops follow commanders from other nations. Multilateralists argue that co-operation strengthens the bonds between nations and peoples, paints the U.S. in a more responsible and respected light, and reduces the risk of wildfire conflicts by increasing the size and unity of the enemy such a rogue nation would face.