If his $825 billion economic stimulus plan is not successful, economists and investors warn that a stock market slide could be more like a 4,000-point stock market crash.

And Americans have vastly more to worry about than just that.

“If the stimulus doesn’t work — and I don’t think it will — we will never have world leader empire status again,” says Lynn Tilton, chief executive officer of the $6 billion private equity fund Patriarch Partners in New York.