Certain Collapse of the American Empire?

Over at MarketWatch Paul B. Farrell has a column, The rise and certain fall of the American Empire, predicting the inevitable demise of American society. He bases his argument on historical precedent set by earlier societies. Farrell outlines a five stage cycle identified by a financial historian from Harvard, Niall Ferguson, that is based on a series of paintings by Thomas Cole called "The Course of Empire":

1. 'The Savage State' before the Empire rises
2. 'The Arcadian or Pastoral State' as the American Empire flourishes
3. 'The Consummation of Empire'
4. 'The Destruction of Empire'
5. 'Desolation' ... after the Empire disappears

Farrell and Ferguson posit that we are between the fourth and fifth stage, and that the coming destruction may be a sudden systemic shock, rather than a slow, protracted demise.

This fatalistic prognostication strikes me as overly pessimistic. What do you think? Is it really too late?