Economic relations between the US and China have become so mutually dependent and potentially destructive that a cottage industry has built up to give them a name. Niall Ferguson, the historian, coined the term "Chimerica" while Zbigniew Brzezinski, Jimmy Carter's national security adviser, proposed the creation of a G2 between the two countries. Even Stephen Colbert, the comedian, has got in on the act, labelling them "frenemies", a mix of friends and enemies.
Just how they intend to approach this complicated dance will become a little clearer over the next couple of days with the first trip to Beijing by Tim Geithner, the US Treasury secretary.
