Vichy France is a nation that can only be created by German Reich following the France capitulation. Is it really worth it though? Should you establish Vichy France in HOI4? It depends.
When playing Germany, I always establish Vichy France because that decision tremendously reduces Allies navy power. Also that allows me to take my focus off from the northern Africa. Besides I can trade lots of rubber, oil and various other resources with Vichy France thanks to the land connection.
So, if you wish to weaken your enemies, always establish the Vichy France. However, experienced player going for a world conquest can conquer all of France and have no problem at all. I would prefer avoiding all the micro-manage.
There is just one thing to keep it in mind. Once enough time passes, Vichy France will demand northern France. If refused, Vichy France will merge with Free France and join Allies. Still, that could be prevented by simply giving northern France to the Vichy France. Eventually they will break their neutrality and completely commit to Axis front.
HOI4 Vichy France
Vichy France cannot be formed or released in HOI4. Only German Reich can create it via event after capitulating France. The moment it created, Vichy France takes control of the Southern France and most of the colonies. As well as a very high percentage of French navy. Which is a pretty good thing for Axis forces.
After a while, Vichy France can join Allies or Axis via focus tree. Also Vichy France will demand the control of northern parts of France from German Reich. If refused, might join Allies and merge with Free France.
I hope this article helps you understand how does Vichy France works in hoi4. If you have anything to add or a question, just leave your thoughts below. That would make me real happy. Anyway, good bye for now, have fun playing Hearts of Iron IV.