Federal, as I have used it, does not mean national.
And federal is just one form of government that works as you indicated.
The United States of America was started as half federal, half national. After Lincoln, it is all national.
There are other types/forms of people getting together in groups. The better ones are voluntary. The best ones are those you can leave at any time.
Ah. So you're saying that all governments should be federal, in that power can be withdrawn at any time?