world government must have sovereign power to deal with problems and issues
which are beyond the scope of national governments because they are global
in nature. A Federal system,
in which the world government is at the center, and national governments
deal with their own parochial issues and problems, is required.
A Federal system is one in which each level of government has sovereign power at their respective levels.
The United States is a Federal government in which sovereignty is shared between the Federal, state and local governments.