Robert Kagan (; born September 26, 1958) is a neoconservative American historian and foreign-policy commentator.
Kagan, however prefers the term "liberal interventionist" to describe himself.A co-founder of the neoconservative Project for the New American Century, he is a senior fellow at the Brookings Institution and a member of the Council on Foreign Relations.
Kagan has been a foreign policy adviser to U.S.
Republican presidential candidates as well as Democratic administrations via the Foreign Affairs Policy Board.
He writes a monthly column on world affairs for The Washington Post, and is a contributing editor at The New Republic.
Kagan left the Republican Party in 2016 due to what he described Donald Trump as a "fascist", and endorsed Hillary Clinton.