The U.S. has been experiencing low growth since the early 1960s because the dollar's been used for global trade. This also led to chronic trade deficits, which started during the 1970s, which in turn prompted the country to promote financial deregulation, or Reaganomics, in order to increase debt and thus meet increased spending, especially for consumers and the military.

In short, for over 40 years, and even after the 2008 crash, the U.S. has been borrowing and spending heavily, to the point that it has to borrow more just to pay for part of the interest of previous debts. Part of the spending went to the American dream, which consisted of taking on increasing credit to buy all sorts of things and financial speculation, like flipping McMansions. Another part went to the military, which with onerous foreign policies was used to keep other countries weak and thus dependent on the dollar for trade. Otherwise, the borrowing stops, spending drops, and the country falls apart.

The problem is that BRICS and emerging markets became stronger, and have been slowly moving away from the dollar and U.S. influence.