Ben Bernanke says it is still vulnerable to “future economic shocks and other adverse events” due to high levels of debt.

"Although historical experience and economic theory do no indicate the exact threshold at which the perceived risks associated with the U.S. public debt would increase markedly, we can be sure that, without corrective action, our fiscal trajectory will move the nation ever closer to that point”, said Bernanke in its appeal to the US Congress to pursue a sustainable path in fiscal policy.