Sorry this answer took a while, it became more than I expected it would when I started writing. Also, I am going to assume that instead of interwar (1918-1939) you meant to say post-war (1945-onward), because that is when the deportation of the Germans from Czechoslovakia took place.

Part 1 of 2

The short answer is very little, but it depends on who you were and when you’re at risk. The forced deportation of Germans (and Hungarians) from Czechoslovakia took place in two stages between 1945 and 1947. The first was spontaneous and accompanied liberation. The second was an official state program based on a series of orders collectively known as the Beneš Decrees and Article 12 of the Potsdam decree which called for “the transfer to Germany of German populations” in Czechoslovakia, Poland and Hungary.

I think it is important to briefly touch on the history of Czech national identity to answer this question, because the idea of a millenarian conflict between Germans and Czechs in Bohemia and Moravia was not new in 1945. In the 19th century a group of historians and linguists started what is known as the Czech National Revival. High society in the Bohemian Crownlands has been increasingly Germanized since the 17th century, and those German-speaking but Czech-identifying Revivalists began to try and construct a Czech culture and language which could be equal to and oppose German culture and language. One of them, František Palacký, wrote a very influential work of history that argued the entire history of the Czech nation was defined by a struggle between authoritative German dominance and Czech freedom. This book has many many flaws (and Palacký’s political agenda was more important than honest historical scholarship) but the idea of this German-against-Czech struggle was very influential on the leaders of the First Czechoslovak Republic like Tomáš Masaryk and Edvard Beneš.

The first point I need to make is that saying “I’m a German” in 1945 requires some explanation because the difference between Czech and German identity was not a fixed line prior to World War II. To be clear, all nations are human constructs and there are also no ‘natural’ struggles between nations. Chad Bryant’s book Prague in Black explains how Czech and German and Jewish identities were individual actions within civil society prior to World War II. During the German occupation, many Czechs were able to become registered Protectorate Germans. In most cases early on, they did not even speak German. Many of the Czechs who registered as Protectorate Germans had done so opportunistically or to secure promotions. I talk about this more here, but the German interest in Czechoslovakia was mostly economic and strategic. Before the war, Czechoslovakia was the 10th most industrialized country and its armaments industry was the 7th largest in the world. Letting Czechs become German was an easy way to ‘Germanize’ the Protectorate of Bohemia and Moravia without sacrificing its significant industrial output. Going back to Bryant, he argues that the experience of World War II and German racial policy is part of what hardened these ethnic categories. If you were a Czech who hardly spoke German but had registered as a Protectorate German for extra rations, social mobility, etc., then you were legally seen as German. I will return to this later in the post, because this will be important once the ethnic cleansing becomes an organized state policy.

So, what happened in the Protectorate during the occupation was not easy for Czech nationalists to reconcile as the war started to end. Despite being a target of Nazi racial policies, the Czech experience of WW2 had more in common with France than with Poland. The country was much less physically damaged during the war than other occupied areas. It was not bombed heavily, the major cities did not see much fighting until the very end of the war, and, with some major exceptions, the Czech resistance was not as large or proactive as the Czechs wished it had been. As Tony Judt puts it, “for the ‘Vichy syndrome’ the Czechs can offer ‘the Munich syndrome’; for overblown résistantialisme and overenthusiastic purges, the Czechs can offer the same thing.” (Judt, Past Imperfect , 2011, p267) To be clear, I don’t think it is fair to judge this from where we sit today. Very few of us have ever faced decisions like they did. This was also not something that could be questioned under the communist government, but since the 1990s this has been something debated publicly among Czechs. Vacláv Havel has some speeches from the early 1990s that mention this period. They were quite controversial at the time, but are a big part of what kicked this off this discussion. If you are interested, Charles University in Prague is making a video game called Svoboda 1945 that is taking part in this reconciliation process. I do not know what I would have done in their position. At the time, the occupation was a difficult historical experience to reckon with, and that is part of what fueled the subsequent ethnic cleansing.

If you were caught up in the first wave of anti-German beatings, torture, lynchings, and deportations that took place during liberation, you were more or less at the mercy of the mob. The actions were spontaneous and unorganized, and not much of an appeal could be made to an external authority or due process. As Chad Bryant argues in Prague in Black , Czech national identity by the end of the war was entirely centered on being anti-German. Anyone who had collaborated was seen as a German, and this also gave nationalists a way to argue that no Czechs could have collaborated. This narrative drew on the Revivalists’ idea of Czech history as an eternal struggle against Germans. The deportation of Germans after the war was in retribution for the occupation, but it was also a way to absolve Czechs of any guilt from collaboration. Czechs did not collaborate because if you had collaborated, then you were German.

As the Soviet and American armies moved into Czechoslovakia, locals took action against individual Germans and perceived collaborators. It was as much a result of personal animosities or neighborhood rivalries as it was based on your national identity. This was not dissimilar to what happened in France and the Low Countries to people who the community decided had committed some form of collaboration during the occupation.

There was some difference in how this happened in the areas liberated by the Soviets and the Americans. Most of Czechoslovakia was liberated by elements of the 1st Ukrainian Front under Marshal Ivan Konev, while the US 3rd Army under General George Patton advanced as far as Plzeň in Western Bohemia. Both the Soviet Union and the United States had supported the expulsions under the Potsdam Decree, but the Soviets were much more directly involved in making it happen while the Americans had a reputation of saving Germans from mob violence. Konrad Henlein, a major figure in the Sudeten Germans Party and leader of the Reichsgau Sudetenland, turned himself in to the American forces based on this, but committed suicide in his cell after the Americans made it clear to him that they would turn him over to the Czechs.