I mean, let’s be honest: People do crimes even when they have no material need to do so, so you will always need some form of law enforcement, how should a solarpunk society handle this?
The same is true for a military: As long as there is no world peace or some magical way to shut the outside world out, and as long as other societies exist somewhere nearby (and in today’s world this means somewhere on the same planet), a society needs the means to defend itself… what would this look like?
The way I see things, law enforcement and military are there to serve and protect those who are higher up in social hierarchies, as well as their wealth, even tho we are fed the story that they work for us, common people. In reality, they are a top-down structure, full of corruption, racism, sexism etc, and I really don’t feel safe around them.
So in order to answer your question, I would need to reframe it. It could be something like: how do people and areas can be protected, from other people or groups of people who are bad actors, within a society that does not have hierarchical structures, meaning that is organized in a horizontal way?
For me, the answer is not a sweeping rigid model that will be applied everywhere, all the time. People from different places see things differently, so local solutions need to be applied. Cultures worldwide have dealt with things. For example, one solution would be to look into their examples and find ideas that would fit for our community’s needs, and take it from there.
(If the questions was about the justice system, I would suggest to look into restorative justice, as well as transformative justice)