Kind, the German investment executive, notes that "the asset quality of Treasurys is unchanged."
The U.S. dollar and Treasurys continue to benefit from a lack of competition, too. Some investors have been trying to diversify away from U.S. dollars by buying euros, Japanese yen or Chinese yuan.
"But all of them have got some significant structural problems," says Michael Every, Rabobank's head of Asia Pacific financial markets research. "The nearest direct equivalent is Europe or the euro, and we know how close they are to crisis on a constant basis."
With the dollar, "you can basically trade it with anyone anywhere and buy and sell a very wide variety of assets with minimal spread and low transaction fees at a moment's notice," Every says. "You can't do the same with the yuan" because China controls trading in its currency.
British consultant Simon Anholt conducts global surveys that consistently show the United States remains the world's most-admired country. He says he doubts the political tussle will do any measurable damage to America's image.
"America is the most-admired country on the planet by a very wide margin," Anholt says. Foreigners "like American culture. They like American products."
He notes that the United States dropped to No. 7 worldwide after the U.S. invasion of Iraq. When President George W. Bush left office in 2009, it quickly bounced back to first place.
Anholt doubts that ay U.S. political crisis will change things.
"We tend to go through our lives with very fixed, sometimes childish clichés about other countries," he says. "We don't change them unless we are forced to."
U.S. politicians have "been trying very hard" to ruin America's reputation, he says, "and they haven't done it yet."
AP Business Writers Christopher S. Rugaber in Washington, David McHugh in Frankfurt, Kay Johnson in Mumbai, Kelvin Chan in Hong Kong and Elaine Kurtenbach in Tokyo contributed to this report.