>>Combat is bad for your ears

Impact noise (e.g. gunshot) is the most damaging to hearing.

But you're right, there are plenty of unknown unknowns here. I think Rumsfeld coined the term; the concept isn't original to him, but the term he came up with gives us something that can be better visualized than "blind spots" - a term I used a lot when designing software.

I think you're right about Putin - and Xi has the same problem in spades - he has no one at all willing to say "yes, but...". I think Putin might be getting "yes, but the cost will be high" from Gerasimov.

Whether Putin is getting the entire story or not, he doesn't seem to have a way to withdraw forces from Ukraine and stay in power - so he's stuck with trying to push through.