When Ireland declared itself neutral at the outset of the second World War, in public at least, the rigid formality of Irish neutrality was maintained for all to see.
In private, however, according to MI5 files released at the Public Record Office in London this week, Ireland was far from neutral. Such was the level of contact between the British and Irish governments on intelligence matters that their correspondence became known as the Dublin link.
Britain viewed Ireland as the weak link in the war against Germany. The British military did not invest much hope of Ireland holding out against the Germans if they landed on Irish shores. In fact, British military strategists judged that it would take little more than one German garrison, perhaps with the help of the IRA, to overrun Ireland in as little as 10 days.
For Ireland at that time, Germany seemed far away, and in the early part of the war at least, neutrality meant little more than maintaining its policy to keep the IRA in check.
Ireland's neutrality and, to a lesser extent at the time, Partition, proved a difficult issue for MI5. "The real weakness of Eire's position and the chief source of danger to this country was that she was at no time capable of successfully defending her neutrality," according to MI5 thinking. From May 1940, when France fell to the Germans, until the German attack on Russia in June 1941, Ireland was considered dangerously open to attack.
The defenceless neutrality of Ireland, recognised by de Valera, rendered Northern Ireland "so vital to the safety of the United Kingdom that it is difficult to contemplate . . . a united Ireland in which British garrisons could only be installed with the permission of an independent Irish government . . .", according to the MI5 file.
While it was recognised that de Valera was "an astute politician", MI5 wondered whether he could have brought Ireland into the war with the Allies in spite of the continuation of Partition and the bitter opposition of the IRA. De Valera might have regarded neutrality as a bargaining tool to end Partition, but MI5 acknowledged that he "may have been politically right" in deciding that as long as Partition remained the Fianna Fail government would not have survived an attempt to bring Ireland into the war.
Once Ireland had established a counterespionage department under the control of the Department of Defence in 1938 with Britain's encouragement, personal relations between British and Irish intelligence officers were "extremely friendly" despite the "strict political control" exerted upon the Irish department in Dublin. When the war began, MI5 generally found itself playing the role of "persuader" when gleaning information from Irish intelligence on German activity. The continuation of the Dublin link (between MI5 and the Department of Defence) was, as far as MI5 could establish, "entirely dependent" on the political relationship between the two governments. The security service noted, however, that when the Taoiseach, Mr de Valera, declared Ireland's neutrality at the outset of the war he added a rider that he would not allow Ireland to be used as a base for operations against Britain. From Britain this position was seen to provide Ireland with the political justification for Irish co-operation with Britain on counterespionage and security matters.
That co-operation led Ireland to pass wireless transmissions from the German legation in Dublin to Britain despite US insistence that the legation should be expelled from Ireland. There was no doubt that the work of the Irish section of the British security service operating covertly in Ireland was also made easier by the Dublin link. When de Valera secured the withdrawal of British garrisons from Ireland's ports in 1938, Britain realised its soldiers in Ireland had been spared "inevitable" German air attacks, which could have rendered Ireland's neutrality untenable.
Increased goodwill between the two countries, which was due in part to de Valera being taken into the confidence of the British government, safeguarded the work of the Irish section in collecting information about German activity in Ireland. The North, too, was a platform for MI5 and MI6 activity during the war as the security services kept a watchful eye on the activities of the IRA, which they feared would betray sensitive military or strategic economic information to Germany.
In 1931, MI5 established contact with the RUC, which was already passing information about "revolutionary and seditious" activity in Northern Ireland to MI6. MI5 discussed in great detail the RUC's shortcomings in providing information about "aliens" operating in the North. "As far as is known, no one on the RUC staff had any knowledge of German or was familiar with German names . . ."
