The security council became the stability council, and now the sustained emergency council. Most of the rest of the UN has fallen away, but UNSEC remains. It servers as a meeting place for national governments and an avenue for mutual aid. The UNSEC can act directly when requested by a member state, in which case it does so through the OS, the Office of Stability. The UNSEC-OS, to give the full acronym, employers military, political, economic and scientific advisors, a rapid reaction force, an investigation arm, and, unofficially, an espionage arm.
UNSEC classifies the world according to politics and habitability. Politically, Earth can be divided into member states, non-member states, and "uncontrolled zones". Prominent member states include the US, USSR, European Union, New Columbia, Angola, Egypt and China. Prominent non-member states include Taiwan, Argentina, South Africa, and Nepal. Prominent uncontrolled zones include western North America between the Mississippi and the Rockies, eastern Europe between Warsaw and the Urals, the Amazon basin, the Indian subcontinent, the Congo, the Sahara desert, and Australia. Uncontrolled zones have no overarching organization, and can be composed of every type of small human society ever conceived, from cartels to cults.
The world is also divided into zones of habitability. "White" zones are controlled
environments, such as domed cities, arcologies, and bunkers. "Green"
zones are suitable for permanent habitation and agriculture. "Yellow"
zones are suitable for long-term habitation, albeit with reduced
life-spans and elevated risks of violent death. "Red" zones are suitable
only for short-term habitation, and can be dangerous even to travel
through. "Black" zones are fortunately rare, zones from which few have
returned and which remain mysterious except for surveillance from a
The default path for PCs is to be members of the OS, which gives them an excuse to get involved in just about anything.