U.S. Allies Watch the Debate With Shaking Heads and a Question: What Now?

During Thursday night’s debate, President Biden told former President Donald J. Trump that the United States is the “envy of the world.”

After watching their performance, many of America’s friends in Asia beg to differ.

In Seoul, Singapore, Sydney and beyond, the back-and-forth between the blustering Mr. Trump and the halting Mr. Biden set analysts fretting — and not just about who might win.

“That whole thing was an unmitigated disaster,” wrote Simon Canning, a communications manager in Australia, on X. “A total shambles, from both the candidates and the moderators. America is in very, very deep trouble.”

Countries that have hoped the United States could balance a rising China and deter North Korea’s nuclear ambitions spent the past four years trying to rebuild ties after Mr. Trump’s first term deeply rattled alliances in the region. The debate on Thursday night immediately resurfaced serious questions about how U.S. politics might affect stability across Asia.

Chan Heng Chee, who served as Singapore’s ambassador to the United States from 1996 to 2012, said the quality of the debates has deteriorated compared with previous ones. Mr. Biden’s disjointed performance and Mr. Trump’s repeated attacks and factual inaccuracies unsettled those who rely on the U.S. to act as a trusted global partner.

“Now everyone is watching for visuals,” Ms. Chan said. “Do the candidates look like they are able to do the job, or is age a problem? Facts do not matter now, and civility has totally gone out of the window.”