The inability of Congress to agree on spending cuts and tax increases to curb the exploding government debt burden creates grave risks, says Michael Strauss, chief investment strategist at Commonfund.

It may come to a point where foreigners are unwilling to finance the now $15 trillion debt by purchasing Treasury securities, he tells Yahoo. Foreigners held $4.7 trillion of that debt as of September.

Political ineptitude has put us in this situation, Strauss says. “We need to operate on both sides of the equation” — spending and taxes, he says. The best ratio would probably be $4 to $8 in spending cuts for every $1 in tax increases, he says.

“But when you have a group in Washington that says no tax increases at all, that sort of prevents negotiations from taking place.”

And the gridlock could mean big trouble. "The danger, given that the U.S. is highly dependent on foreign flows, . . . is at some point, the foreigners may say 'enough is enough, I don't want to buy this debt,'" Strauss says.

We could go the way of Europe “if we can’t get our fiscal house in order,” Strauss says.

Ironically enough, Treasury yields have dropped to record lows in the midst of the U.S. fiscal crisis. While investors partly have sought Treasurys as a safe haven from Europe’s woes, they apparently view Treasurys as a hedge against U.S. fiscal problems too.