Absolute monarchs, by definition, have absolute responsibility for all decisions made by their government.
Nick made the decision to take Russia into a war for which it was woefully unprepared, resulting in the deaths of millions.
He also bears at least some moral responsibility for repressive policies in the years before the war, including support of pogroms against the Jews, repression of democratic movements that might have led towards a constitutional monarchy, etc.
Alexandra shares this responsibility because it was well known that he was heavily influenced by her.
BTW, I didn’t say I necessarily believed their fates deserved. I said it is possible to make such an argument, which it is.
I've read that what passed for brinkmanship in those days was mobilization, and once the extremely expensive task was started, it sort of took on a life of its own, as egos measured the capabilities of each other.
You would think "Nick" would have learned from getting his buttocks kicked by Japan.