Doctrine (Latin: doctrina) is a code of beliefs or "a body of teachings".
Doctrine often means several religious dogmas that a church teaches. But it can also mean a principle of law, in the common law traditions, established through a history of past decisions, such as the doctrine of self-defense, or the principle of fair use.
In matters of foreign policy, a doctrine, also known as dogma, is group of fundamental rules for a nation's foreign policy. Examples include the Monroe Doctrine, the Stimson Doctrine, the Truman Doctrine, the Eisenhower Doctrine, the Nixon Doctrine, the Brezhnev Doctrine, the Kirkpatrick doctrine, and the Bush Doctrine.