Remember the last time the country came to the brink of default? It was August 2011. For the first time in history, Standard & Poor’s, the ratings agency, downgraded United States government debt.

“The effectiveness, stability, and predictability of American policy making and political institutions have weakened at a time of ongoing fiscal and economic challenges,” it said. Investors around the world rushed to find a safe place to put their money.

Rather than dump America’s downgraded bonds, however, investors flocked to them. The dollar strengthened. The United States might have become a threat to the world economy, but with even worse troubles developing elsewhere, including a flare-up in the euro crisis, it was still its safest place.

As George Soros, the hedge fund investor, told me in an interview last Friday, “The dollar is the weakest currency except for all the others.”