It is one of the greatest what-ifs of Irish history. In the summer of 1940, the Luftwaffe prepared to launch its blitz over London and Nazi forces swept across Europe. British officials quietly proposed something unthinkable. A United Ireland, on the condition Éamon de Valera abandon neutrality and bring Ireland into the war.
Recently released documents from the Public Record Office in London reveal just how far Britain was willing to go. The proposal included an immediate declaration accepting “the principle” of Irish unity, the formation of a Joint Defence Council, and a constitutional body to negotiate the merger of Northern Ireland and the South. It was bold. It was desperate. And it failed.
At the heart of the plan was Malcolm MacDonald, the British Secretary of State for the Colonies, dispatched to Dublin for ten tense days of private talks. MacDonald dined with Dev, flanked by key cabinet members Seán Lemass and Frank Aiken. McDonald laid out a vision that, in his words, could make a united Ireland a reality “within a comparatively short period of time.”
But there was a catch. Dublin would have to renounce our treasured neutrality. British troops, ships, and aircraft would be granted access to Irish territory. Ports like Cobh and Berehaven, once critical under the Treaty Ports agreement, would be reopened to the Royal Navy. And though de Valera was offered the option of remaining “non-belligerent,” the practical effect was clear. Ireland would become an active participant in the Allied war effort.
For Churchill, the Western Approaches were vital in the Battle of the Atlantic. German U-boats were choking Britain’s supply lines. Irish ports could offer lifelines. But for de Valera, the stakes were existential. He listened. He debated. And he refused. Why? Because de Valera did not trust Britain to deliver.
As he told MacDonald on the 26th of June, the proposal was a “deferred payment". A promissory note, not a guarantee. Lemass likewise pointed out the lack of immediate action on unity. And when MacDonald admitted that London “would not and could not march troops into the six counties to force a policy upon their government,” the illusion cracked.
There would be no coercion of Unionists. No swift reunification. Only a vague hope that the North might voluntarily agree to dissolve itself. Aiken questioned whether Britain’s security could be safeguarded even if Ireland remained neutral. But MacDonald dismissed the idea, calling Northern Ireland’s role in the war “most valuable.”
And yet MacDonald pushed further. Dropping his official role, he appealed personally. As a man who claimed to support Irish unity. He warned that if Éire stayed out of the war, if it was seen to “contribute to German strength by doing so,” then after the war “none of us in Britain would be very concerned to create a united Ireland.” Dev argued that accepting British troops on Irish soil would fracture the nation and provoke the very fate they hoped to avoid, a German bombardment. “They would bomb Dublin,” he said simply.
And he wasn’t wrong. A German air raid did hit the North Strand in 1941, killing 28 and injuring hundreds. Neutrality didnt offer perfect safety, but joining the Allies couldve made Éire a battlefield. De Valera had other doubts. He believed Britain might lose the war. Within Fianna Fáil, there were tensions over any policy that smelled of renewed submission to Britain.
And there was the lingering trauma of partition itself. In the end, the offer vanished into the fog of war. Unionist Prime Minister James Craig in the North was incensed when he learned of it. Perfidious Albion moved on.
Dev kept Ireland out of the war, despite Churchill’s later frustrations. But for a brief lunchtime, Britain offered a united Ireland, in exchange for war. It might have changed everything. Or, as de Valera feared, it might have changed nothing at all.
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