Idk about Yezhov, in Ukraine all men have to go fight so it's not like he made a naive decision at all, it was not his to make in the first place if that makes sense.
The idea that you “have to” fight is abdicating your moral responsibility. He chose to fight.
Doing that had a major personal cost, but I wasn't willing to fight for a immoral regime. It wasn't Ukraine, and perhaps the calculation in Ukraine would have been different, but the point is that claiming one doesn't have a choice is an excuse, nothing more. What it's really saying is that one isn't willing to pay the price for making a difficult choice.