Courtesy of DoubleLine’s Fall of Roman Empire presentation on 2/14/2012:

 

The implications: government will issue more debts to cover the debt rollovers. Hard assets such as precious metals (Gold) will be sought after.

See also

Is This Your Family’s Financial Statement?

Sovereign Debt and Deficit by Country

Fed Member: A Leveraged ETF Hedger And A Gold Bug?

Harry Browne’s Permanent Portfolio Long Term Performance