Well it would mean that we would have a total collapse of the financial system. People wouldn't be able to get any loans for houses which would make the housing crisis get much worse than it already is, people wouldn't be able to borrow to get cars, and people wouldn't be able to get the capital to start small businesses. Also big business wouldn't be able to raise capital which would mean no new investment and possibly would have to lay off even more workers than it already is and many would have no choice but to shut down since they have no sources of liquidity. In other words think of the great depression all over again. Unemployment was around 25% then. We have a long way to go and I'm sure you have never seen the sort of poverty that would be spread all over the country and bleed into others all over the world. When people are rioting in the streets over it I'm pretty sure that would then be a national security problem.