What if Hitler had invaded?

ANALYSIS: Dublin’s Gauleiter was to have sweeping powers which could have meant the liquidation of trade unions and the GAA, …

ANALYSIS:Dublin's Gauleiter was to have sweeping powers which could have meant the liquidation of trade unions and the GAA, writes TOM CLONAN

SEVENTY YEARS ago this summer, Adolf Hitler’s general staff drew up detailed plans to invade Ireland. In June of 1940, Germany’s 1st Panzer Division had just driven the British Expeditionary Force into the sea at Dunkirk.

The Nazis, intoxicated by their military victory in France, considered themselves unstoppable and were determined to press their advance into Britain and Ireland. Germany’s invasion plans for Britain were codenamed Operation Sealion. Their invasion plans for Ireland were codenamed Unternehmen Grün or Operation Green.

Like Operation Sealion, Operation Green was never executed. The Nazis failed to achieve air superiority over the English Channel that summer. By the autumn of 1940 the Battle of Britain had been won by the Royal Air Force (RAF) and Hitler postponed his British and Irish invasion.


Some military historians also believe that the plans for Operation Green, drawn up in minute detail, may have been a feint to divert British resources away from Germany’s invasion of southern England. However, had the RAF been overwhelmed that summer by the German air force, the Luftwaffe, Operation Green gives a sobering insight into what fate neutral Ireland would have suffered at the hands of the Nazis.

Operation Green was conceived under the scrutiny of Field Marshal Fedor von Bock. Bock had a fearsome reputation as an aggressive campaign officer – well versed in the concept of Blitzkrieg. Bock had been commander of Germany’s army group north during the invasion of Poland in 1939 and army group B during the invasion of France in May of 1940. Nicknamed Der Sterber, or Death Wish, by his fellow officers, von Bock was ultimately given responsibility for Germany’s planned assault on Moscow (Operation Typhoon) during Germany’s subsequent invasion of Russia.

In the summer of 1940 however – before Hitler had turned his attentions towards Russia – von Bock was preoccupied with invasion plans for neutral Ireland and assigned responsibility for it to the German 4th and 7th army corps, army group B under the command of General Leonhard Kaupisch.

If these German army units in particular had reached Ireland’s shores in 1940, the consequences for Ireland would have been tragic and would have profoundly altered the course of history for the Republic and its citizens.

The German 4th army corps in particular had a brutal reputation in battle and inflicted many civilian casualties as they secured the Polish corridor to Warsaw during the invasion of Poland in 1939. Later in 1941, the 4th army corps, equipped with its own motorised infantry and Panzer tank divisions, would play a crucial role during Operation Barbarossa, Hitler’s invasion of Russia. The 4th army corps, earmarked for service in Ireland in the summer of 1940, conducted brutal operations the following summer as they took Minsk and Smolensk on their advance to Moscow in June and July 1941.

Had the 4th and 7th been deployed to Ireland in 1940, their tactics would have been brutal and their advance rapid – up to 100km per day.

The Nazis allocated 50,000 German troops for the invasion of Ireland. An initial force of about 4,000 crack troops, including engineers, motorised infantry, commando and panzer units, was to depart France from the Breton ports of L’orient, Saint-Nazaire and Nantes in the initial phase of the invasion.

According to Operation Green, their destination was Ireland’s southeast coast where beach-heads were to be established between Dungarvan and Wexford town. Once they had control and airstrips had been established (negligible armed resistance was expected) waves of Dornier and Stuka aircraft would have started bombing military and communications targets throughout the Irish Free State, as it then was, and Northern Ireland.

In the second phase of the invasion (to start within 24 hours of the first landings), ground troops of the 4th and 7th army corps would have begun probing attacks, initially on the Irish Army based in Cork and Clonmel, followed by a thrust through Laois-Offaly towards the Army’s Curragh Camp base in Co Kildare.

Their rate of advance would have been rapid, with some units reaching the outskirts of Dublin within 48 hours of landing in the southeast.

The capital city was identified by the Nazis as one of six regional administrative centres for the British Isles had occupation taken place. Dublin’s Gauleiter was to have sweeping executive powers and would have had instructions to dismantle, and if necessary, liquidate, any of Ireland’s remaining indigenous political apparatus, her intellectual leadership and any non-Aryan social institutions such as the trade union movement or the GAA, for example. Irish Jews would have been murdered en masse.

Hitler’s generals were aware that their operations in Ireland would have to be self-sustaining given that their troops would be operating far from the continental mainland in Europe’s most western region.

Adm Raeder described the German force in Ireland as one which of necessity “would be left to its own devices” in order to execute its mission of conquest. Therefore, Operation Green envisaged that German troops here would administer martial law and curfews, commandeering shelter, food, fuel and water from the civilian population. The plans even contained an annex with the names and addresses of all garage and petrol station owners throughout Munster and the midlands.

This policy of predation on the civilian population would have inevitably led the Germans into direct conflict with civilians as they confiscated livestock, food, fuel and used forced labour to support their advance northwards. As was the case in continental Europe, Irish civilians would have borne the brunt of the casualties in an invasion, either through the vagaries of war, punitive actions by the Germans or through the almost inevitable counter-attack by Britain.

In military terms, the Irish Army would have been wholly ill-equipped to challenge a German invasion in the summer of 1940. In 1939, there were approximately 7,600 regulars in the Army with a further 11,000 volunteers and reserves of the Local Defence Force, forerunner of the FCA. By May 1940, this number had dropped by 6,000 due to financial constraints. The Irish government’s recruitment campaign only began to bear fruit by the autumn of 1940.

Had the Germans come ashore in the summer of 1940, they would have been met by an Army with no experience of combined arms combat and capable only of company- sized manoeuvres, involving a maximum of about 100 men. In addition, the Irish Army was poorly equipped, possessing only a dozen or so serviceable armoured cars and tanks. In terms of small arms, the Army did have plenty of Lee Enfield rifles – of first World War vintage – but had only 82 machine guns in total for the defence of the entire State.

Many Irish units also moved about on bicycles – referred to at the time as Peddling (or Piddling) Panzers. Had they been engaged by the Wehrmacht, the Irish would have been slaughtered.

Ironically, the Germans were not the only foreign power making plans for the invasion of Ireland in the summer of 1940. In June of that year, Gen Montgomery drew up plans for the seizure of Cork and Cobh along with the remainder of the Treaty ports.

When Britain’s prime minister, Winston Churchill, became aware of Operation Green, the British military set out detailed plans to counter-attack the Germans from Northern Ireland. Codenamed Plan W, it envisaged Irish Army units regrouping in the Border areas of Cavan-Monaghan and being reinforced by British troops moving south from Northern Ireland. In this scenario, the Irish and British armies would have fought alongside one another to repel the German invasion.

Had this happened, it is hard to see that widespread casualties, military and civilian, would not have ensued.

Of course, neither Operation Green nor Plan W were implemented. Ireland survived the war almost entirely untouched by it, thanks largely to its neutral status being respected by the combatants and the crucial role played by the RAF in the summer of 1940.

Were it not for the sacrifices of the 544 British, New Zealand, Czech, South African, Canadian, Polish, Australian, French and some Irish who fought and died with them during the Battle of Britain, who knows what flag would now fly over Leinster House.

Tom Clonan is Irish TimesSecurity Analyst.

He lectures in the School of Media, DIT.