Isn't Earth's Starfleet part of the UESPA?
Or UESPA is part of Earth's Starfleet. Or the two are equal partners in whatever joint venture that shield seen in ENT "Demons" symbolized.
Its possible that that things like the Warp Five Complex were under UESPA jursidiction until it and possibly other manned space exploration related programs were merged to form Starfleet shortly before Archer joined.
It's also possible that a Starfleet existed in some form or another long before Archer's Starfleet was founded. After all, the same holds true for Kirk's Starfleet...
I wouldn't be at all surprised if the United States had a Starfleet in the 2010s in the Trek universe!