Well I am just going by the view of the Common German Soldiers and Officers who fought on the Eastern Front.
I agree they were badly led, badly armed, badly supplied, but they were not lacking in courage and a resilience to conditions that even the Germans found hard to bare.
re :On longer scales, the claim is directly falsified - tyrannies lose wars to republics much .
Which claim is this.
If its this.
The Germans and Soviets when well led made better soldiers, coming from dictatorships where life was cheaper, they were able to withstand the horror and death of war. many also were brought up in martial environments the Hitler Youth and Kommosol both had a strong death and glory cult
I stand by it, and its a claim that many Allied senior soldiers on the British and American side made.
You stand by it, and it is rot. Tyrannies in which life is cheap generally produce not better soldiers, but men ruled by fear, cronism and selection for loyalty rather than merit among leaders, lack of initiative, lack of technical means from stunted innovation, to the letter obedience to non-sensical orders issued by out of touch REMFs, useless waste of military material, and tactics as good as the enemy could wish for.
Ruthlessness is not a source of strength, it is a source of weakness. The contrary belief is a piece of rank superstition that is belied by all the evidence of history. The illusion arises from men doing violence to their own conscience and thinking it affects the enemy. It doesn't, but sometimes it prevents cooperation, and generally it dramatically reduces motivation as well.
Justice is the standing policy of the most successful states in history because it simply generates vastly more power through elicited support than tyranny ever can. The parts of the world that believe ruthlessness is the secret of power, to the point where men are willing to eat each other to scare their enemies, are hopelessly backwaters of impotent chaos.