Saudi Arabia December 21, the Arab news network published the American university professor at Columbia University, the university, director of the center for sustainable development, the United Nations sustainable development action network chairman Jeffrey sachs, entitled "the United States has become rich, the rich, the rich of the nation" the article said, a year ago, Joe biden, a narrow victory in the election, Donald trump, But America's prospects remain uncertain. It is not easy to diagnose exactly what has got America into such trouble that it has stoked the "Trump movement".