if any actions were taken that would be considered a breach of neutrality

One instance was the Donegal Corridor, which allowed Allied aircraft stationed on Lough Erne at the most westerly point in the UK to extend their range an extra hundred miles into the Atlantic by overflying a seven-mile strip of Irish territory.

Another was the practice of passing reports from Irish Meteorological Service stations to the Allies but not to the Germans. One such report was crucial to the decision to postpone the Normandy landings for 24 hours due to incoming adverse weather on the target date.

There was also Plan W, a joint strategy for defence of the island in the event of a German invasion. Such was the level of co-operation envisaged that the Irish Army changed their uniforms to match those of the British, in order to reduce the possibility of friendly fire.

Yes, Ireland was neutral, but as the saying went at the time, everybody knew who they were neutral for.

Ireland's neutrality was solid throughout the war. That stance was not shaken even in June 1940, when British diplomatic initiatives, to the horror of Northern Irish Unionists, offered Irish unity in return for participation in the war effort, including British use of Irish ports and the establishment of air bases. Even the Charlie Chaplin movie "The Great Dictator" was banned, in case it should be interpreted as showing undue pro-Allied tendencies. There were numerous such cases throughout the war right through to 1944, when despite allied pressure, the Irish government refused to expel their German and Japanese diplomats from Dublin.

Another famous example was when the United States entered the war and Churchill sent a message to the Irish Taoiseach reading: "Now is your chance. Now or never. A nation once again," yet this overture was turned down.

This being said enthusiasm for the Nazis was scant and in a secret cabinet meeting in 1941 they resolved that, should the Nazis invade Ireland, they would be resisted by every means and British aid would be requested.

Despite all of this neutrality was important for Ireland. Despite 50,000 Irish serving in the allied forces it has to be understood that they were a newly forged nation and neutrality was understandable in a war that did not concern them. To the bitter end neutrality was upheld and Eamonn de Valera in May 1945, paid an official visit of condolence to the German legation in Dublin upon Hitler's death which became infamous and extremely controversial.

On a parting note of Irish neutrality, sometimes they get quite some stick with people referencing de Valeras visit as proof of lacking a backbone or indeed moral fibre. But Irelands neutrality has to be understood alongside the history of the nation. Ireland had been fighting against British rule intermittently since 1170 when Richard "Strongbow" landed with the first English troops. Over the next 800 years very few historians can avoid the harshness at times with which the Irish people were treated. Whether it be the during Cromwells campaign 1649-50 when massacres occurred infamously in Drogheda which he claimed as "a righteous judgment of God upon these barbarous wretches." Or indeed during the famine where British disinterest and negligence compounded the severity of the situation.

These things remained in the Irish collective thought of Britain and so the easy decision for others, not 20 years after Irish independence, of "the good allied powers" against the "evil axis powers" wasn't as strongly held in Irish society as it may naturally have been to others.

Source: Ireland: History of a Nation by David Ross