Currently, the "Pax Americana" is based on the military preponderance beyond challenge by any combination of powers and projection of power throughout the world's "commons"—neutral sea, air and space. This projection is coordinated by the Unified Command Plan which divides the world on regional branches controlled by a single command. Integrated with it are global network of military alliances (the Rio Pact, NATO, ANZUS and bilateral alliances with Japan and several other states) coordinated by Washington in a hub-and-spokes system and worldwide network of several hundreds of military bases and installations. Neither the Rio Treaty, nor NATO, for Robert J. Art, "was a regional collective security organization; rather both were regional imperia run and operated by the United States". Former Security Advisor Zbignew Brzezinski drew an expressive summary of the military foundation of "Pax Americana" shortly after the "unipolar moment":