In World War II, Operation Grün was the Nazi invasion of Czechoslovakia which began on 14 March, 1938.

The areas of Czechoslovakia with a majority of ethnic Germans were peacefully ceded to Germany on 1 October, 1938 at the infamous Munich Conference. The Czechs were therefore without their formidable border defenses. When the Germans invaded, the Czechs were abandoned by their British and French allies. They surrendered with only local resistance.

The Germans annexed the Czech areas and created a puppet Slovak Republic in the east. The destruction of Czechoslovakia outflanked Poland to the north in much the same way as the annexation of Austria had outflanked the Czechs themselves.

Czechoslovakia was recreated after World War II but has since divided itself into Slovakia and the Czech Republic.


In World War II, Operation Grün (Green) was also the German codename for the decoy invasion of Ireland planned in conjunction with Seelöwe, in 1940.

Like Herbstreise ("Autumn Journey"), barges were to be sent towards the south coast of Ireland to give the English the impression of a widescale sea invasion of the British Isles. To convince British Intelligence of the plan, German operatives led by Hermann Goertz were parachuted into Ireland to make contact with the Irish Republican Army (I.R.A.) and to initiate a bombing campaign throughout Ireland and Northern Ireland. This part of the operation was known as Plan Kathleen. The I.R.A. targets would be the British embassy in Dublin, various police and military posts in Northern Ireland and to destabilise the government of Eamon de Valera.

In final stage of the operation, once the I.R.A. bombing campaign had finished, a 32,000 strong German paratrooper force led by General Kurt Student would parachute into two zones in Northern Ireland. One south of Lisburn to sever the railway and communication lines between Belfast and Ireland and to destroy the RAF airbase at Long Kesh, while the second to land north of Belfast and capture the RAF airfields at Nutts Corner, Aldergrove, and Langford Lodge. The Luftwaffe would then be able to strike targets in Scotland and the west coast of England.

A side benefit of the plan would be that fearing Ireland may fall into the hands of Germany, England would be then forced to invade neutral Ireland thus earning the condemnation of the United States, which was not yet at war.

The operatives however reported back to Germany that the I.R.A. were "unreliable" and "undisciplined" and would take months to train. The operation was finally scrapped when Seelöwe was placed on indefinite hold and the operatives captured by the Irish police.

A modified bombing campaign by the I.R.A. in conjunction with the Luftwaffe aerial bombing over England was later planned in 1941, codenamed Artur ("Arthur").