Research Affiliates’ Rob Arnott says the U.S.’s debt problems may not come home to roost in the short term, but they have him very concerned about the long term.

“I think there’s a dislocation because the market is priced as if things are back to normal, and the simple fact is that they’re really not,” Arnott says in an interview with IndexUniverse.com. “We’re looking at head winds from a debt overhang that’s vast.”

Arnott says the federal deficit and debt are actually much higher than the officially reported figures if you use GAAP accounting principles. He says issues like how to fix Social Security and Medicare haven’t gone away. “These are not issues that can blow up in our faces in the next six to 12 months,” he says. “These are things that could happen in the next six to 12 years. So, they represent head winds. And when the gusts of that storm become intense, the markets will feel it. And right now, the markets are kind of shrugging it off.”

One thing the U.S. does have going for it, Arnott says, is its position as a “safe haven”, so turmoil like that which we’ve seen in Egypt leads to inflows into the U.S.

Overall, Arnott says he doesn’t try to predict short-term market movements. But he does say that now is not the time to add risk to your portfolio.