Defence Forces ( Ireland ) The military of Ireland , known as the Defence Forces ( , officially styled ) encompass the Army , Naval Service , Air Corps and Reserve Defence Force . The Supreme Commander of the Defence Forces is the President of Ireland . All Defence Forces officers hold their commission from the President , but in practice the Minister for Defence acts on the President ' s behalf and reports to the Government of Ireland . The Minister for Defence is advised by the Council of Defence on the business of the Department of Defence . Role . Ireland ' s favourable geographical location , on the north - west border of the European Union , makes any external threat or future invasion unlikely . The state has a long - standing policy of non - belligerence in armed conflicts that included neutrality in World War II . For these reasons , the Republic ' s military capabilities are relatively modest . However , the state has a long history of involvement in United Nations Peacekeeping operations . Functions of the Defence Forces include : History . The Irish Defence Forces trace their origins to the Irish Volunteers founded in 1913 . The Defence Forces official title , Óglaigh na hÉireann , is taken from the official Irish language title of the Irish Volunteers . The Defence Forces cap - badge , and the buttons that are worn on Service Dress no . 1 uniforms are also from the Irish Volunteers . The Defence Forces buttons still have the letters I V ( Irish Volunteers ) on them . Volunteers led by Patrick Pearse , took part in the 1916 Easter Rising . After the rising the Volunteers gave allegiance to the First Dáil . At this time the Volunteers became known as the Irish Republican Army ( IRA ) . The IRA waged a guerrilla campaign against British rule in Ireland between 1919 and 1921 . A Truce brought hostilities to an end on 11 July 1921 and the Anglo - Irish Treaty was signed on 6 December . The Provisional Government was then constituted on 14 January 1922 . Many IRA men who fought in the War of Independence were dissatisfied with the Treaty and both Civil War or reoccupation by the British were possible . In February 1922 , the Provisional Government began to recruit volunteers into the new Irish National Army . The Irish Civil War began on 28 June 1922 between the Republican Anti - treaty IRA and the newly recruited pro - treaty National Army . The Civil War ended on 24 May 1923 , Frank Aiken IRA Chief of Staff ordered IRA volunteers to dump arms and the new Irish Free State slipped into an uneasy peace . On 3 August 1923 the new state passed the " Defence Forces ( Temporary Provisions ) Act " , raising " " an armed force to be called Oglaigh na hEireann ( hereinafter referred to as the Forces ) consisting of such number of officers , non - commissioned officers , and men as may from time to time be provided by the Oireachtas . " " The establishment of the Forces was on 1 October 1924 . The state was officially neutral during World War II , but declared an official state of emergency on 2 September 1939 and the Army was mobilised . As the Emergency progressed , more and newer equipment was purchased from Britain and the United States . For the duration of the Emergency , Ireland , while formally neutral , tacitly supported the Allies in several ways . German military personnel were interned in the Curragh along with the belligerent powers ' servicemen , whereas Allied airmen and sailors who crashed in Ireland were very often repatriated , usually by secretly moving them across the border to Northern Ireland . G2 , the Army ' s intelligence section , played a vital role in the detection and arrest of German spies , such as Hermann Görtz . Ireland became a member of the United Nations in 1955 . The first contribution to peacekeeping was in 1958 when Army officers were assigned to the United Nations Observer Group in Lebanon ( UNOGIL ) . Since 1958 the Defence Forces have had a continuous presence on peace support operations . The first armed peacekeeping mission was to the Operation des Nations Unies au Congo ( ONUC ) in 1960 . The Defence Forces have been continuously on armed UN missions — except between May 1974 to May 1978 but did retain overseas unarmed observer missions during this period . In October 2009 , a memorial to Irish personnel who served as United Nations peacekeepers was unveiled in the town of Fermoy . It records that there was a total of ninety Irish fatalities while on active service with the UN until that date . Organisation . The Defence Forces consist of a Permanent Defence Force ( PDF ) which is a standing force and provides the main capability for military operations , and a Reserve Defence Force ( RDF ) which to support the PDF if necessary . The RDF is consist of the First Line Reserve and a Second Line Reserve . The First Line Reserve comprises former members of the Permanent Defence Force and the Second Line Reserve comprises an Army Reserve and a Naval Service Reserve . The Defence Forces are organised into three service branches : Army , Naval Service , and Air Corps . Army . The Irish Army has 8 , 500 active personnel , and 13 , 000 in the Army Reserve . Up to late 2012 the army had three brigades : the 1st southern , 2nd eastern and 4th western . However , at 2 pm on 30 November 2012 the 4th western brigade stood down at its HQ Custume barracks , Athlone . The country is now divided into two areas for administrative and operational reasons with the old 4th western brigade split between the other two brigades , and in each area there is an Infantry brigade . In addition to the Brigades Structure , there is also a Defence Forces Training Centre ( DFTC ) , a Logistic Base in the Curragh and a number of special establishments such as the Equitation School , Army Bands , and the Army Ranger Wing . In the case of Corps which support the Infantry , a Corps Director and staff are provided to co - ordinate the purchase of specialised equipment , the execution of specialised training , etc . The two brigade group structure envisages distinct operational areas of responsibility for each of the brigades . The First Brigade has primary responsibility for operational tasks in South half , the Second for operational tasks in the north half . Practical operational considerations dictate the requirement to outline operational areas of responsibility . The brigade group structure is based on strengthened combat and combat support elements and streamlined combat service support elements . The Army has nine specialist Corps , each designated as either combat , combat support or combat service support . These are the Infantry Corps , Artillery Corps , Cavalry Corps , Engineer Corps , Ordnance Corps , Medical Corps , Transport Corps , Military Police Corps , Communication and Information Services Corps . Irish infantry are equipped with assault rifles , machine guns , grenade launchers , hand grenades , and anti - tank weapons . Most weapons used by their defence forces follow NATO standards , and are purchased from abroad , with Ireland having a very limited arms industry . The Irish Army has light armoured vehicles , with the primary vehicle being the MOWAG Piranha , armed with machine guns . The Irish Army also use the FV101 Scorpion armoured reconnaissance vehicle , equipped with a 76mm low velocity gun and a 7 . 62mm machine gun . Its artillery capabilities consist of 120mm mortars , 105mm howitzers , 81mm mortars , and 60mm mortars . Air Corps . The Irish Air Corps is the air component of the Defence Forces . The Air Corps HQ is at Casement ( Baldonnel ) Aerodrome . The Air Corps is the smallest of the branches of the Defence Forces , with approximately 939 personnel , and its primary roles are defined as : There are two secondary roles : The Air Corps is tasked with the traditional air force role of defending Irish airspace however its capability to do so is severely limited . The Air Corps now prvide SAR ( search and rescue ) back up to the Coast Guard . Irish Coast Guard . The Air Corps ' helicopters are the only helicopters within the State capable of flying at night in mountain terrain using Night Vision Goggles . The Air Corps ' two CASA CN - 235 maritime patrol aircraft are equipped with detection systems and assist the Naval Service in patrolling Irish territorial waters and EEZ . These aircraft are also used for HALO ( High - Altitude , Low - Opening ) parachuting by the elite Army Ranger Wing . The Air Corps has six AgustaWestland AW139 utility helicopters capable of being armed with FN MAG machine guns . These advanced helicopters can be flown using Night Vision Goggle and used in support of the ARW , Naval Service and Gardaí operations . Seven Pilatus PC - 9 turboprop aircraft equipped with rocket pods and machine guns , two Eurocopter EC135 light utility helicopters , which can be used as sniper platforms by the Army Ranger Wing , are used for training pilots and air ambulance missions . There are also a number of auxiliary aircraft . Naval Service . The Naval Service maintains a complement of about 1 , 144 personnel , and is tasked with policing Irish territorial waters as well as the Irish Conservation Box a large area of sea in which fishing is restricted to preserve numbers . The Naval Service is tasked with enforcing this EU protected area and thus serves the EU as well as Ireland . The Naval Service , together with the Air Corps and Customs , have intercepted a number of vessels carrying narcotics to and from Ireland . The Navy has eight offshore patrol vessels which are operated in support of the service ' s main roles , inflatable seagoing craft , and training vessels . The Naval Service maintains highly trained armed boarding parties that can seize a vessel if necessary , and a special unit of frogmen called the Naval Service Diving Section . While the Naval Service does not have any heavy warships , all of the naval vessels have enough firepower to enforce their policing roles . The primary role is defined as " National Security " , with secondary roles which include : Representative Associations . The interests of members of the Defence Forces are represented by a number of representative associations similar to trade unions . Commissioned Officers of the Permanent Defence Forces are represented by RACO . Rank - and - file members of the Permanent Defence Forces are represented by the Permanent Defence Force Other Ranks Representative Association ( PDFORRA ) . PDFORRA is affiliated to the Irish Conference of Professional and Service Associations ( ICPSA ) and to the European Organisation of Military Associations ( EUROMIL ) . In 2009 , members of PDFORRA took part in the Irish Congress of Trade Unions ( ICTU ) protest against the government ' s handling of the 2008 – 09 financial crisis . The Department of Defence warned that Defence Forces members could not take part in or sponsor any " public agitation " , and that PDFORRA had " no express permission " for members to take part in the protests . All ranks of the Reserve Defence Forces are represented by RDFRA . Bases . The Defence Forces operate a number of bases throughout the Republic of Ireland :