Short answer: no.
In the original game manual, pages 26-27, there's a description of Earth history leading up to the launch of the sleeper ships (emphasis mine):
By the end of the twenty-first century, mankind had seen bold and unprecedented changes within the world. Radical new technologies were surfacing at incredible rates.... In the wake of the eradication of Communism from the Eastern Nations, nuclear weapons quickly became available in abundance. The international power structure... was blasted apart as third-world nations rose to challenge [the superpowers].
Popular sentiment held that the world was plummeting towards an inevitable catastrophe as overpopulation and genetic alteration swept across the globe.... Horrific acts of terrorism and violence erupted between the corporate sector and the humanist factions, resulting in forced police actions across the globe.... Ultimately, the precarious balance of world power exploded into international pandemonium.
On November 22, 2229, the United Powers League was founded. The UPL was to become the ultimate incarnation of the vision of a unified humanity held by the now-defunct United Nations.... The UPL was founded on the basis of "enlightened socialism", but often resorted to harsh, fascist police actions to maintain public order.
From this, it seems unambiguous that the old social order, nations and all, had essentially fallen apart by the time the UPL came around, with special emphasis on the collapse of Communism. The UPL itself seems to have foundational ethics from all over the place; certainly it has some Stalinist elements, some Communist ideas, but it isn't a direct descendant of any one single Earth ideology or nation.
When they realized that the Terrans in the Koprulu sector had discovered intelligent alien life, the UPL was reorganized into the UED with the express aim of defending Earth by any means necessary (read: purge all the xenos).
