Like many people, I was surprised when the Russians started military actions in Ukraine.
When it happened I understood why it had happened in general terms. I believe that if things had happened just very slightly differently that there would have been no invasion. Also, that invasion was not a part of the plan when the training manoeuvres started.
Anyway, I wanted to understand the decision process a bit better. Of course, we will never, at least in my lifetime, know exactly what happened to start the military operation. But I did find out about a possible decision structure and process that might have been in play, either in a formal or informal manner.
That structure is the Ten Man Rule.
In essence, and possibly very badly explained by me - the idea is that on a planning team, one person, the 10th Man has the job of looking at the situation as devil's advocate. The one who looks at the worst possible outcome of a situation and feeds that back to the planning group or structure.
Here is a shortish paper on the topic. It ain't a hard read. https://www.academia.edu/31660435/The_Tenth_Man_rule_in_reality_EN_and_DE_Leonhardt_2021_