>>2579875 (OP)Germanic autism and spergery, similar to the Anglos.
Germany allowed their autism and sperg-like behaviour to consume them throughout their historiography which, combined with their intellect and military prowess, caused other world powers, even other Germanic ones who learned to tame their sperginess, had teamed up to destroy.
tl;dr, Germanic autism and failure to contain caused Germany to be ganged up on more than once.