The public ones are partly there to generate an official public decoy or “honey pot”, and for other practical reasons. But of course there are others. And the full scope of the officials ones are secret.
It’s pretty clear at this point that the major factions vying for information and power at this point are not limited to nations, and in fact the nations seem to be more and more secondary official side-shows that similarly act as decoys and honey pots for attention, and to generate official stories to distract and satisfy most people.
Meanwhile, the real concentrations of power remain anonymous, diversified, and secretly pulling strings and quietly gathering information and wealth and power and so on.
For example, see the expose of RAND Corporation as a tool of the international corporatocracy in Confessions of an Economic Hitman.