Starfleet Command

Starfleet Command is an organization that predates the United Federation of Planets. Founded prior to the year 2140, it began as a military arm of the United Earth government even before that entity was considered to be completedly formed.

The Federation Charter expressly permitted member worlds to maintain their own defense forces, and most did so. Earth, however, did not. Instead, it turned over Starfleet Command to the full control of the Federation, trusting the Federation's need to defend its own center would mean Earth was protected.