French guy here.
So in our history books, we talk much about the French resistance during WW2 and how it helped them to turn the tide (even though the American landing did the most of the job). Basically, a lot of people simply rejected the defeat (which was actually signed in 1940) and started resisting.
But what I don't really understand is why there wasn't any sign of "resistance" in Germany after they lost WW1. Even though their soil wasn't invaded, they got stripped of some territories, and a lot of their cities were occupied by Allies forces. But there isn't a trace of acts of sabotage, silent killings of Allies, and operations to free some cities. They seemed to simply endure the defeat and the Treaty of Versailles, until Hitler's rise to power which led to WW2.
We could say that Hitler would basically be their way to resist but they had to wait for 15 years until the Nazi party went into full power and started to refuse the Treaty of Versailles. French, on their part, resisted as soon the armistice was signed.
So was there a post-WW1 German resistance that we don't talk about, or did it never exist at all?
I know it's not the thrust of your question but it's worth noting that the French did not start resisting "right after" the armistice.
To simplify immensely, the immediate reaction from the French population, after the shock of defeat had worn off, was one of cautious acquiescence and attentisme. Generally people waited to see how the war would pan out and whether there would be an early peace. Active physical force resistance didn't begin, in any mass sense, until June 1941 when the German invasion of the USSR freed the French Communists from their uncomfortable neutrality. Post-armistice, the first German soldier in France wasn't killed until 21 August 1941. Even when 'the Resistance' did kick into gear, it was a multifaceted movement that took different cues from Moscow and London as to how to best hinder the Germans. Even/Especially if we limit the scope to armed resistance, the process of 'starting resisting' was rarely straightforward.
And I say 'simplify' above because if the French example has proven anything, it's how complex attitudes towards 'resistance' actually are. It's not just physical violence but also the more ambiguous attitudes towards disobedience, survival and self-preservation. I'd suggest that at least some of these are visible in post-1918 Germany - and not just the obvious example of the Ruhr occupation - but will leave that to someone better qualified.
The issues are a couple compounding things:
In other words the people voted to leave Germany. Inside of Posen and generally the lands given to Poland the land was pretty universally ethnically Polish majority and the national sentiment reflected that. In fact Poland's focus would be more focused on the Soviet Union invading them in 1919 more than anything else.
On October 24th, 1918 the Imperial Navy began in numerous locations to mutiny. By the 4th of November over 40,000 sailors and the soldiers who joined them would have captured Kiel and the surrounding areas; their spread would only continue. By the 7th Hanover, Brunswick, Frankfurt, and even Munich were captured by mutinying soldiers and sailors. Workers, socialist workers, began to flood their ranks as the Bavarian aristocracy was kicked out and a "Bavarian Soviet Republic" was founded. In the East while they would be spared from mass Socialist revolution would suffer from ethnic Poles uprising en masse. Even Berlin would be wrapped up in the seemingly unending conflict between the SPD and those who aligned with them and the Conservatives.
Beyond all of this though there was sabotage of Versailles and it was not violent but economical. Sally Marks' The Myths of Reparations is probably the most conclusive analysis of this in existence at the moment and the prognosis is not good for the early Weimar administration: They deliberately sabotaged their own economy to get out of them. The French and British honestly did not expect the full amount to be paid and planned to reduce it. However the policies of Rudolf Havenstein, the Finance Minister from 1908 to 1923, deliberately conspired with other areas of the German government to sabotage their own economy to get out of war reparations and to, more importantly, deprive France of needed reparations.
Since the Germans had absolutely no intent of even pretending to act in good faith by 1923 they occupied the Ruhr and, at the same time roughly, Havenstein would die. These two combinations would knock some sense into the German government and give them the opportunity to fix it; between 1923 and 1929 Hjalmar Schacht would be the architect which brought the German economy back on its feet. They paid their reparations (which were nearly halved due to Havensteins actions!) and experienced 5 whole years of being 'in the green' and experience rapid economic growth. It would only be America's collapse (who were heavily invested in the German economy themselves) that would cause Germany to go tumbling down harder than anyone else in the world. Who knows; maybe an extra 5 years between 1918 and 1923 of actively trying to fix rather than hurt their economy would have left them better off; but that's a little too alternate history to tell.
OP, have you seen Le chagrin et la pitié?