Just talking about it is causing problems. The Dow is dropping, the IMF is issuing warnings, and now Asian markets are sagging:

TOKYO — Asian share prices sagged on Wednesday as the U.S. budget deadlock dragged on and further chipped away at investors' confidence that a deal will be reached before a mid-October deadline to avoid a debt default...

"Everyone had been thinking that U.S. politicians will become grown-ups in the end. But some people are starting to think they look too childish to become grown-ups in time," said Tohru Yamamoto, chief fixed income strategist at Daiwa Securities.

The Republican response: shrug.