The PDF includes the Army, Naval Service and Air Corps.

The Reserve Defence Forces consists of the Army Reserve (formerly An Forsa Cosanta Aitiuil - FCÁ) and the Naval Service Reserve (formerly An Slua Muirí).

The president is the Supreme Commander of the Defence Forces but this role is mainly symbolic. Military Command is exercised by the Government through the Minister for Defence.

The roles of the Irish Defence Forces as decided by Government are:

• to defend the State against armed aggression.

• to aid the civil power (in practice this means to assist, when requested, the Garda Síochána, who have primary responsibility for law and order, including the protection of the internal security of the State). This includes cash, explosive, and prisoner escorts.

• to participate in multinational peace support, crisis management and humanitarian relief operations in support of the United Nations and under UN mandate, including regional security missions authorised by the UN;

• to provide a fishery protection service in accordance with the State's obligations as a member of the EU;

• to carry out such other duties as may be assigned to them from time to time, e.g. Ministerial air transport service, assistance on the occasion of natural or other disasters, search and rescue, air ambulance service, assistance in connection with the maintenance of essential services, assistance in combating oil pollution at sea, ceremonial duties such as St. Patrick's Day parades.

The Army (PDF) today contains approximately 8,500 soldiers. The Army is organised into three brigades; the 2nd Eastern Brigade, the 1st Southern Brigade, and the 4th Western Brigade. Each brigade contains combat units such as infantry, combat support units such as artillery, and combat service support units such as supply and transport. In addition to the three brigades is the Defence Forces Training Centre, the Equitation School, a logistics base, the Army Bands, and the Army Ranger Wing (Special Forces). Each brigade is designed to fulfil the functions in its area of responsibility.

Each brigade of the Army (PDF) contains a Brigade Headquarters, three Infantry Battalions, one Field Artillery Regiment, one Cavalry Squadron, one Field Engineering Company, one Field Communications Information Services Company, one Military Police Company, one Logistics Support Battalion, and one Brigade Training Centre.

The Army Reserve is currently in the process of reorganisation to 'mirror' the PDF structure. This means that units are being merged, renamed and relocated.

For more information on the reorganisation of the Army Reserve Click Here

The Naval Service is based in Haulbowline, Cobh, County Cork. It consists of a flotilla of one helicopter patrol ship, five offshore patrol vessels and two fast coastal patrol vessels. It's roles are similar to those of the Army but also include: Fishery Protection, Aid to the Civil Power, Drug Interdiction, Maritime Safety, Diving Operations, Pollution Control. Naval Service ships make courtesy visits to European and other international ports and undertake annual overseas supply missions to the Irish troops serving with the United Nations missions. Fishery protection is one of the Navy's most common tasks. The Naval Service is responsible for patrolling the 320 kilometre (200 mile) economic zone which includes 340,000 square kilometres (132,000 square miles) of sea and ocean. In it's fishery patrolling the Naval Service operates with the Air Corps two CASA maritime patrol aircraft.

The Naval Service consists of a PDF element with a strength of approximately 1,100 and an RDF element with a strength of approximately 400.

The Air Corps is based in Baldonnel, County Dublin and consists only of PDF members. The role of the Air Corps is to defend the airspace of the state and support the Army, Naval Service and Garda Siochana. The Air Corps operates approximately 30 aircraft ranging from trainer aircraft to ministerial jets.