The possibility that the U.S.is in decline has renewed concerns over the international strategic situation and the global order.The World Bank's International Comparison Program (ICP) released data in April 2014 that suggested China' s economy could overtake that of the U.S.as soon as the end of this year (based on purchasing power parity or PPP which takes into account the relative costs of goods and services and inflation rates).Their figures showed that the size of China' s economy was 87％ of the U.S.' in 2011—that is 15％ bigger than previously estimated.China' s economy is thought to have grown roughly 24％ since 2011,while the U.S.economy is expected to have grown less than 8％.2 The possibility that the U.S.economy is in decline has worried both the public and scholars,and has sparked a new round of lively debate on the future of the international strategic situation.