The Washington Doctrine of Unstable Alliances, sometimes called the "caution against entangling alliances", is a contemporary term used to describe an early realist United States foreign policy guiding its interaction with other nations. According to the policy, the United States should consider external alliances as temporary measures of convenience and freely abandon them when national interest dictates. It has been cited as a rare example of an explicit policy endorsement of what, in international relations, is known as renversement des alliances ("reversal of alliances"): a state abandoning an ally for an alliance with a recent enemy, sometimes against the former ally.