"Apart from that, Mrs. Lincoln..."

Progress, far from consisting in change, depends on retentiveness. When change is absolute there remains no being to improve and no direction is set for possible improvement: and when experience is not retained, as among savages, infancy is perpetual. Those who cannot remember the past are condemned to repeat it.^{--Jorge Agustín Nicolás Ruiz de Santayana y Borrás, Reason in Common Sense, 1906}

Plus ça change, plus c'est la même chose

All I have to say is: https://youtu.be/kPIdRJlzERo?si=JF6zvjx66d2AwoTl

German gouverment has tried to initiate a rebellion in ireland to keep England busy with intern problems during WWII, they evend wasted some of their rare submarines to get agents over the channel (a order what drived Admiral Dönitz insane), so there could have been a connection. Also Ireland had a hard history with england like the starving-crisis in the 19.century without much help (and more mocking) from London, guess memories like that tried the nazi's to use.

While Germany did try to land submarines off the coast of Ireland in World War I (most notoriously, in the case where they actually did land Sir Roger Casement, who was later captured and executed for treason), in World War II, Germany's espionage and subversion efforts in Ireland were minimal. There were a small handful of ineffectual agents, which were under the sharp eye of Irish counter-intelligence (working, surprisingly, with Allied counter-intelligence). I actually have some personal family history in this regard, since my grandfather's older brother (my grand-uncle) was head of Irish Army intelligence and, during the war, commander of one of the Irish Army's divisions. The British did suspect the Germans would try to use submarines, but they never did -- a matter of priorities when Germany needed every operational submarine for the Battle of the Atlantic. de Valera, personally, was cold toward the British (and hated the American ambassador to Ireland, who was a jerk), and was stiff-necked and stubborn. To be sure, there was a current of irritated feeling against England, but there was also a feeling against Germany, as well, because of its persecution of the Catholic Church (this, in an era were Ireland was arguably the most Catholic-minded country in Europe). The Famine/Great Hunger of the 1840s (and a later one in the 1870s) was largely a folk memory by 1940; the real source of hard feeling toward England in 1940 was the Civil War of the 1920s.

Interesting inside-view. Guess I have remember wrong it, been a while with my german navy researchings. Hitlers persecution against the church is difficult to view, he even payed tax-money to the church and let gouverment-offices manage their paperwork (but this is a very old german issue we try to fix since Weimarer Republik), on the other side a Priest get executed for telling a Hitler-Joke ( besides other things)

The question of Irish Republican Army activities during the War is a separate one; while the Germans would have dearly loved to have worked hand-in-glove with the IRA, and the IRA did carry out some subversive activities, the Irish Free State was also fearful of the IRA (for different reasons), and successfully kept a lid on their activities.