If partial default:
Short term- A mild economic downturn, followed by a lot of legal action and butthurt sturm und drang by whichever party was affected, and a lot of scolding David Broder articles.
Long term- Slightly higher interest rates relative to expected return on future US government borrowing.
In the unlikely event of a total default:
Short term: A worldwide economic meltdown that will make the Great Depression look like the credit crunch of 1772.
Long term: Higher interest rates relative to expected return on future US government borrowing.
Obviously markets would plunge and interest would spoke, and there would be large global recession (depression?) but what would be the political and economic effects down the line, domestically and internationally?
You go down the list of the world's countries, ask yourself, 'what would happen if a massive recession hit this country?' and add them all up.
They would lose their US bonds.
No.