Many in Britain have never forgiven de Valera for Ireland's neutrality. And in Northern Ireland that status was seen as an act of treachery by a country that was still a member of the Commonwealth. In contrast Northern Ireland's record was proud: it provided manpower for the British forces and bases for the Royal Navy and Royal Air Force in the Battle of the Atlantic, while its industries contributed towards the war effort.
But Irish neutrality was not a black-and-white issue. This neutral nation provided aid to Britain in the form of intelligence-gathering facilities, permission to fly through Irish air space and the repatriation of Allied airmen forced down in Ireland. At Killybegs in County Donegal there was even a British air-sea-rescue vessel based for much of the war, although the Robert Hastie actually appeared on the books of HMS Ferret, the naval base at Londonderry.
Irish support for Britain came in an even more tangible form. Tens of thousands of Irishmen and women joined the British forces.
Conscription was never extended to Northern Ireland; so anyone who joined up from either side of the border was a volunteer. The relative figures have long been a subject of controversy and the tinkering with the figures that took place in the latter phase of the war and its immediate aftermath did not help matters.
A reasonably accurate figure for Irish enlistment can be arrived at by studying the Army's roll of honour at the Public Record Office, Kew.
There are over 170,000 names on the roll, giving a death ratio of one- in-22 for the wartime Army. Analysing the entries to find the Irish-born shows a total of just under 4,400 Irish dead. Using the known ratio of dead to serving this works out at over 98,000 Irishmen in the Army alone, some 2 per cent of the Army's strength.
It is not possible to carry out a similar exercise with the same degree of accuracy for the Royal Navy and the Royal Air Force but, assuming a lower Irish strength of 1 per cent in either case, we can arrive at figures of 9,500 in the Navy and 12,000 in the RAF. The overall total of Irish service personnel would, therefore, be about 120,000, of whom the majority, about 100,000, volunteered during the war.
Using the place of birth information from the Army roll of honour, it is also possible to arrive at figures for enlistments from each side of the border. These are: almost 68,000 from southern Ireland and 52,900 from Northern Ireland. Interestingly this increases by about 10,000 the figure claimed for Northern Ireland enlistments. But it also shows that for every individual from Northern Ireland in the British forces there were 1.3 from south of the border. The population of the south was then about twice that of Northern Ireland so that its proportionate contribution to the British forces was not much smaller than that of its neighbour.
But, of course, the southern Irish had no part in this war. Many decided to fight because they opposed the evil that Nazism represented. One veteran summed up the typical attitude by stating that Hitler was a bully and had to be stopped; if his country wasn't going to join in stopping him, then he would do so himself.
In opposing Fascism southern Irishmen won eight Victoria Crosses while another VC went to a Belfast sailor. Interestingly the proportion of Irish VCs won during the war was over 4 per cent, twice the proportion of Irishmen in the services. In itself that figure makes a profound comment on the contribution made by a neutral nation to the Allied cause in the Second World War.
Richard Doherty is the author of `Irish Men and Women in the Second World War' (Four Courts Press, pounds 19.95)