This is a file of running notes from 2026 that will catch mostly what I'm reading.
Frank McDonough's The Weimar Years: rise and fall 1918-1933 is a solid pocket history of the 15 years encompassing the Weimar Republic. It's a companion to two other volumes he's written on the years when Germany was governed by a well-known dictator.
There was of course no "root cause" for the fall of the Weimar state: root cause analysis was abandoned by serious forensic engineers decades ago as a misleading simplification of the wandering path toward failure that leads up to the collapse of any complex system. That said, a few points stand out.
The Kapp Putsch in 1920 was an attempt by military insiders to overthrow the early Weimar government. It failed, but the leadership got off lightly, with Kapp himself serving less than 18 months. Does that sound familiar?
The Weimar constitution itself was badly designed: presidential democracy is inherently unstable against dictators, and Weimar's partisan proportional electoral structure made the Reichstag even weaker than most congresses when it came to reining in executive power, which was typically wielded by a chancellor who had been appointed by the president but who nominally required Reichstag approval.
Article 48 of the constitution gave the president wide-ranging powers to rule by decree, which allowed a sufficiently motivated chancellor able to manipulate a weak or aging president to become dictator by constitutional means, which eventually happened. It would have happened regardless.
The French were no help at all, nor were the German Left, as represented by the SPD (social democrats) or the KDP (communists, inevitably in Moscow's pocket) who couldn't work together and as time passed failed to work with anyone else as well. Ideological purity for the loss.
France's obsession with punishing Germany is an object lesson for the future. We'd all like to reduce the enemies of democracy and liberty to dust. Maybe we should instead be willing to extend the hand of friendship to them... after we've tried and executed the ringleaders, and perhaps a handful of innocents as well, because that always happens. But if the USians had put Robert E Lee and Jefferson Davies and their cronies to the sword back in the day, we'd likely be living in a better world now.
The global economic crisis was a gift to the NSDAP, which they used well.
Weimar Germany was a progressive, tumultuous society that could have given us a leg up on modernity. The combined forces of its constitutional fragility as a presidential democracy, the hostility of the Allied powers to German economic recovery, the fragmented nature of German society itself, the failure of the republic's defenders to believe in their own virtue and kill those who would take up arms against it, and finally the world situation after 1929 all contributed to its failure.
No doubt someone will one day write a similar history of our own era, although it will have a much happier conclusion if we learn any of the lessons that the past is trying to teach us.