The Irish Army. Approximately 8,500 men and women serve in the Irish Army, divided into three infantry Brigades. Since 1958 the Irish Army has had a continuous presence in peacekeeping missions around the world as well as its maintaining its primary roles of defending the State and internal security within the State. The Irish Army also participates in the European Union Battlegroups. The Air Corps and Naval Service support the Army in carrying out its roles. - Source: Wikipedia