In 2024, the Republic of Ireland joined NATO's Individually Tailored Partnership Programme (ITPP) in order to increase its' capabilities at countering potential threats to undersea infrastructure.

Additionally, there were fears that the United Kingdom, eager to secure Irish ports for their air and naval forces, might use the attacks as a pretext for an invasion of Ireland.

Ireland also secretly allowed Allied aircraft to use the Donegal Corridor, making it possible for British planes to attack German U-boats in the mid-Atlantic.

While both Axis and Allied pilots who crash landed in Ireland were interned,[3] downed Royal Air Force airmen were repatriated.

Ireland continued their policy of military neutrality during the Cold War, though the country aligned economically and politically with the west and joined the European Communities (EC) in 1973.

It was passed with the government arguing that its opt-in nature allowed Ireland to "join elements of PESCO that were beneficial such as counter-terrorism, cybersecurity and peacekeeping... what we are not going to be doing is buying aircraft carriers and fighter jets".

[20] There has been, and continues to be, a minority of individual politicians and groups of politicians who support Ireland joining NATO, mainly but not limited to the centre-right Fine Gael party (in 2013, the party's youth wing Young Fine Gael passed a motion calling on the Irish government to start accession talks with NATO).

[24] They have also proposed a constitutional amendment to prohibit the country from joining a military alliance like NATO, though the Dáil has so far rejected the associated legislation, most recently in April 2019.

[28] However, in June 2022, after the Russian invasion of Ukraine had begun, Taoiseach Micheál Martin stated that there was no legal requirement for a referendum on the matter since it was "a policy decision of government”,[29] though he later clarified that politically it would be necessary.

The Irish government began supplying military and civilian air facilities in Ireland for use by the armed forces of the United States during the 1991 First Gulf War.

Following the September 11 attacks in 2001, the Irish government offered the use of Irish airspace and airports to the US military in support of the war in Afghanistan and the 2003 invasion of Iraq, on the condition that aircraft be unarmed, with no cargo of arms, ammunition or explosives, and do not engage in intelligence gathering, and that the flights in question do not form part of military exercises or operations at the time.

[33] Casement Aerodrome, Baldonnel (military) and Shannon Airport (civil), used as stopover hubs, have seen more than 2.4 million American troops pass through from 2002 to 2014.

[36] According to leaked American diplomatic cables (WikiLeaks) from the US Embassy in Dublin, the Irish Minister for Foreign Affairs at the time told the chief of mission that the Irish authorities suspected the CIA had on a number of occasions used aircraft disguised as commercial flights to transfer prisoners detained in Afghanistan to Guantanamo Bay, Cuba for interrogation and detention – using Shannon to refuel in the process – and warning of the legal implications for both Ireland and the United States as a result.

[40] In February 2015, two Russian Tupolev Tu-95 "Bear" nuclear-capable strategic bombers flew close to Irish airspace without entering it, with their transponders switched off and failed to file flight plans, causing serious concern at the Irish Aviation Authority (IAA), which was forced to divert a number of civil passenger aircraft out of the path of the Russian bombers as a precautionary measure.

[42] The fact that Russian military bombers carrying nuclear weapons flew within 12 nautical miles of the Irish coast caused significant alarm.

The long-range surveillance radar is reported to cost €10 million, and is seen as a priority purchase to provide the civilian and military authorities with an improved competency in monitoring aerial incursions.