Irish military to be permitted to use force in support of An Garda Síochana

For the past 60 years, it has technically been illegal for military personnel to use their weapons to defend the State.

A legal anomaly meant, in almost all circumstances, military personnel were restricted to using force only in self-defence or the defence of their comrades.

Now, with the introduction of new rules of engagement, that has changed. When acting in support of the Garda, military personnel will be permitted to use force in a much wider array of circumstances if State security is at stake.

Strict rules will continue to apply however. For example, the Defence Forces will have to liaise with civilian aviation authorities when drafting rules of engagement for air defence, according to documents seen by The Irish Times.

The new rules are, in part, a response to the growing airborne threat posed by hostile drones and are designed to clarify the legality of shooting down manned and unmanned vehicles. They apply to sailors, soldiers and aircrews when they are acting in support of Garda security operations.

Work began on implementing the broader rules of engagement earlier this year, in advance of Ireland taking over the European Union presidency last July.

The new rules will be in operation this week when Defence Forces personnel, as part of Operation Fianna, will deploy in a security role during the visit of about 50 heads of government for two high-level meetings in Dublin.

The Defence Forces operation, which is being run by the joint taskforce in McKee barracks, will oversee the deployment of naval vessels in Dublin Bay and anti-aircraft batteries around the capital.

Various aircraft will patrol overhead including Defence Forces helicopters and PC-9 aircraft tasked with shooting down low-flying airborne threats.

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The Defence Forces’ previous use-of-force regulations, introduced in 1967 and known internally as COD 6, permitted military personnel to use force only in a narrow set of circumstances.

A soldier could use force in self-defence, in defence of a military post, in defence of fellow security personnel and in defence of government property.

Over the years, military officers raised concerns that these rules were overly prospective and did not permit force to be used against a threat to civilians or civilian infrastructure.

Following the September 11th attacks in the United States in 2001, Air Corps officers pointed out they would technically not be legally permitted to shoot down a hijacked aircraft over Ireland.

However, the argument was mostly theoretical as the Air Corps lacked aircraft capable of reaching the speed and height of commercial airliners.

In recent years, Army and Air Corps officers have raised similar concerns when it comes to hostile drones over civilian areas.

The new rules of engagement were implemented during the summer following the passage of the Criminal Law, Civil Law and Defence (Miscellaneous Provisions) Act 2026, which amended the Defence Act 1954.

The new legislation states that when deployed in support of gardaí, Defence Forces personnel “may use such force as is reasonable, proportionate and necessary in the performance of his or her duties”.

As previously announced, the new law also allows Naval Service personnel to seize ships in Ireland’s exclusive economic zone.

The new rules give military management significantly more flexibility in drafting rules of engagement for on-island security operations in support of the Garda. However, sources said these new rules would remain extremely strict.

Last July, Minister for Defence Helen McEntee sent a letter to Chief of Staff Lieutenant General Rossa Mulcahy instructing him to begin training personnel in the new rules.

She said the changes introduce “significant” new powers for the Defence Forces and that “extensive and ongoing measures” would be needed to ensure their appropriate application.

The general was ordered to review the new rules after two years and report back to the Minister.

McEntee told the chief of staff that the military must consult and liaise with certain civilian authorities when exercising these powers in the air domain.

In response to queries, a Defence Forces spokesman confirmed training on the new rules have already begun but that it could not provide specific details “due to reasons of national and operational security”.