The Group of Two (G-2 or G2) is a proposed informal special relationship between the People's Republic of China and the United States of America. Originally initiated in 2005 by C. Fred Bergsten as primarily an economic relationship, it began to gain wider currency and scope from foreign policy experts as a term recognizing the centrality of the Sino-American relations near the beginning of the Obama Administration. Prominent advocates include former National Security Advisor Zbigniew Brzezinski, historian Niall Ferguson, former World Bank President Robert Zoellick and former chief economist Justin Yifu Lin.