Can America Have a Debt Crisis?

"S&P warns that the US could be downgraded again if it fails to create a "credible" fiscal plan" from this site.

It is clear that nervous investors will shift their investments into safe havens in the face of uncertainty.

It is true that most modern economies carry a huge amount of debt to equity.

Currently, the US has a debt to equity ratio of 1.  How long can the US sustain this ratio if GDP is growing at a rate of 2.4%?  I believe a debt crisis can and will affect the United States.  I predict that it'll be the middle east oil countries that help us out.