Investors view default by U.S. Treasury as more likely than Coca-Cola
online.wsj.com
online.wsj.com
The US government has the ability to raise taxes and has organisations which can enforce these tax rises and an army to defend itself. It also has vast assets that it can sell off. Whilst the market might think that the Treasury is more likely to default than Coca-Cola, the markets don't represent reality in this instance.
I'm not an expert on what occurred, but I believe the Russian government thought process was something along the lines of: -We could either sell off all the country's assets OR -Default on debt now, have a bad reputation with future foreign investors, but not shrink our country further.
They went with option B.
Not saying this would or will happen to the USA, but theoretically it could.
California has been teetering on the edge of default -- not always making payments on time -- despite having the ability to raise taxes. CA also owns vast assets it too can sell off.
Admittedly we'll probably see places like Greece, Italy, Spain and Portugal default first, but it can happen here too.