Those who want to dive deeper into the interrelation between history, geography, sociology and mentalities, I want to point to the Annales school[1], a group of French historians that formed in the late 1920s and had a big impact on historical studies, first in France and later world-wide. They are famous for their interest in what they called the "longue durée"[2], long-term historical processes.
However, one must be very careful not to draw too hasty conclusions from supposedly simple geographical correlations. Two example from the Twitter thread:
"West Germany (1949-1990) was extraordinarily similar to Germania as planned by Caesar Augustus c. 1 AD, to East Francia at the Treaty of Verdun in 843 AD, and to the Confederation of the Rhine in 1808." -- Whether there existed really an elaborated, dedicated plan to extent Roman rule up to the Elbe, is quite controversial among historians. Be that as it may, the Romans where not successful anyway, so hypothetical borders East and North of the limes could not have had any practical impact. -- The borders of the Treaty of Verdun are indeed quite similar to those of West-Germany. But it lasted only 27 years (from 843 to the Treaty of Meerssen in 870), when its Western border moved more Eastwards (and even more in 880 with the Treaty of Ribemont). -- The Confederation of the Rhine was a short-lived alliance of Napolionic client states. It was formed in 1806, its extent in 1808, Mecklenburg and Saxonia, does not really fit the borders of later West-Germany and by 1812 Napoleon incorporated the Netherlands and all of North-West Germany up to the Elbe into France. -- So this similarities are simple coincidences. There are geographical elements (the Rhine, the Elbe, ...) which played a role in defining borders from time to time. But there are really a lot of them during the centuries, with the borders constantly changing.[3] So it is no wonder that one finds something that roughly fits modern borders at some time in the past.
As to the maps of "Catholicism and Nazism" (or rather Protestantism and Nazism): This maps clearly show that the election results from 5 March 1933 of the NSDAP (National Socialist German Workers' Party) correlate with Protestantism. However, the conclusion that Protestants were on average more responsible in Hitler's coming to power is not compelling. Even though Hitler had already become Reichs-Chancelor on 30 January, the NSDAP received "only" 43.9 % of the votes. What finally established his dictatorship was the "Enabling act" of 24 March 1933. Only the SPD (Social Democratic Party of Germany) voted against it.[4] (The Communists were already been arrested or in hiding.) If you now look at a map of the opposing SPD's election results from 1933, you will see that it is also confessionally correlated, but this time with Protestantism.[5] To understand all this, one has to consider that there existed a dedicated Catholic party, the Deutsche Zentrumspartei (or short: "Das Zentrum"), that had a considerable loyal following of voters. This party played no role in the Protestant parts of Germany. Alas, when it become dangerous to oppose Hitler, this Catholic party sided with Hitler and only the (more "Protestant") SPD resisted.
[1] https://en.wikipedia.org/wiki/Annales_school
[2] https://en.wikipedia.org/wiki/Longue_dur%C3%A9e
[3] Just look at this map from showing the extent of the "Holy Roman Empire" during the early 13th century: https://en.wikipedia.org/wiki/Holy_Roman_Empire#/media/File:...
[4] https://en.wikipedia.org/wiki/Enabling_Act_of_1933#Voting_on...
[5] https://www.wahlen-in-deutschland.de/wuKarteSPD.htm
