 Founded in the mid-1920s following the Anglo-Irish Treaty, the Office of the Directorate of Intelligence was originally the intelligence arm of the Irish Army, hence its code-name "G2", which is a designation in NATO's continental staff system used to refer to an army intelligence, security, and information branch.Later the Directorate became the intelligence service for the entire Irish armed forces, hence it is now referred to as "J2" (which refers to joint services, i.e.the Army, Naval Service and Air Corps) and took on more national security roles.