Without specifics, there is nothing more I can really say. Any mistakes the Soviets made were made after the historical pressure of a long, bloody, civil war with it’s fair share of foreign interventions. Pardon me if I don’t trust the Monday morning quarter-backing of westerners three generations later. The spd did what they did, they sullied their hands and chose to ally with reactionary violence. Perhaps they would do differently in a colonial national liberation setting, but trusting soc-dems to overturn the imperial state for worker’s emancipation is a fool’s game. They will never do it, and they will call you a red authoritarian while you are being beaten by the cops.

There is genuinely no singularly better book to understand the nature of fascism and how it historically develops within a country, and is facilitated and aided by liberals than Blackshirts and Reds.

If they have only two historical criticisms, one of which has very little to do with the entire argument in light of other historical evidence, and another one that is ‘Waaaaah he wasn’t sufficiently mean to the USSR.’ then I consider that peanuts, considering how generally completely fucked liberal history is over these events.

Edit: It sounds like you are talking to people who seem to think that western communists are in any kind of position similar to the kpd, spd and Soviets, as if there is really a lesson to be learned here for our time. There isn’t. Our soc-dems are even more reactionary than the spd were, our communists weaker and more fractured, and there is no one who has actually done the thing to even write to for advice. Why collaborate with those who don’t share your principles when it doesn’t matter anyways? Compromise only when there is actually something you think you can materially get done. Volunteer, help the unhoused, etc. But there is no reason to politically support the soc-dems in the imperial core, now more than ever. They will be running dogs.