Hans Joachim Morgenthau (born 1904 in Coburg, Franconia; died 1980 in New York City) was a German-Jewish political scientist and jurist who had to escape the repressions of the Nazi dictatorship and emigrate to the United States (where he became a citizen in 1943). He studied philosophy and law in Frankfurt a.M., Munich, and Berlin between 1923 and 1927, spent his legal clerkship in Frankfurt, earned a doctorate in international law in 1929, and subsequently served as a judge at the Frankfurt Labor Court.

From 1932, Morgenthau conducted research as a private lecturer in public law at the University of Geneva and, after his forced eviction from his home country due to the Nazi takeover and the loss of his judgeship in Frankfurt (National Socialist ban on Jewish Germans from profession), he turned entirely to political science after migrating to the United States. However, his second book, written in Geneva in 1933, was already primarily concerned with the political (La notion du "politique"). Morgenthau researched and taught as a political scientist at leading American universities (e.g. Princeton University, Yale University, Harvard University, University of Chicago, Columbia University or Berkeley University) within the framework of more than 20 visiting professorships.

With his major work Politics Among Nations. The Struggle for Power and Peace (1948, dt.: Macht und Frieden. Grundlegung einer Theorie der internationalen Politik), Morgenthau is today considered the "founding father" (Hoffmann in Thompson/Clinton 2005: xvii) of the political science discipline of International Relations (IR), whose intellectual influence on political science and beyond can hardly be exaggerated. His thoughts on the importance of power and the significance of its balance in international relations (balance of power), on the role of state leadership as a mediator between inside and outside while safeguarding the national interest, or his warning against excessive nationalism and excessive ideologization of politics as factors promoting war are canonical today (and highly topical in view of global developments).

His opus magnum is considered one of the most cited works in the arena of IR (Jacobs 2003: 35). A study of the memoirs of 30 leading IR scholars found that Hans Morgenthau is by far the most frequently mentioned name in the memoirs of these leading thinkers. (Kruzel in Mearsheimer 1995: 47) Despite the emergence of new IR theories, it should be noted that parts of his book Politics Among Nations "have become legend among students of international relations" (Gallarotti 2010: 142).

The list of Morgenthau publications is long and shows his multi-faceted output (https://sites.google.com/site/ymiya181/). The flowering of Neoclassical Realism in IR in recent years demonstrably attests to Morgenthau's academic "rediscovery" as well as the ongoing relevance and continuity of his ideas.

Morgenthau was a recipient of the Grand Cross of Merit of the Federal Republic of Germany. He was a member of the prestigious organizations American Academy of Arts and Sciences and the American Philosophical Society, among others. He also served as a long-time trustee of the Carnegie Council for Ethics in International Affairs. His circle of friends included Hannah Arendt, Henry Kissinger, John F. Kennedy, Hans Kelsen, and Reinhold Niebuhr.

Through his political, academic and private contacts, Morgenthau was very involved in the possibility of emigration of Soviet Jews to Israel as well as against the Vietnam War. A "stumbling stone" at the Casimirianum Coburg commemorates him today.