Taxes. You need taxes. Just like how you run the military.
> then what happens if tax revenues are low one year
You tax the top iter of the society to make up for it. Just like how it is done for the military.
> Even communist countries own assets
In no communist country, the well being of their people or societal infrastructure ranging from transportation to military to police or education, was tied to the market. Even today there are many capitalist countries that dont do that.