I was not in the military but like almost everyone I have a lot of family members who were, and I also have a couple who are very ranking members of the air force. I dont know if I’d say it should be a requirement to have military experience but there are some important things learned in the military in regards to leadership that is very rare for civilian life, and in a situation like this would make a huge difference.
Take for instance the chain of the command and delegation. Not only do members of the military have a clear understanding who is in charge, but when they have “specialists”, they understand heavily that you let the specialists do their jobs. You learn that a leaders job is to take responsibility for what arises, deflection is much less likely.
Almost every job teaches skills and you can get many important skills in civilian work, but the military provides a unique experience in leadership, delegation, teamwork, putting others needs in front of your own, and a plethora of other things that having success in the military can be a very good thing for the leaders.
In fact, Id venture to bet, most of the “best” leaders had military experience.