Most of the people think that US Dollar aka $ is very stable and can never crash. If you think so, think again!

One should read this section in the article in Wikipedia: The mechanics of U.S. Government debt Even though US debt has been increasing dramatically, the inflation in US (and the dollar value) has been under control mainly because China has been willing to accumulate dollar denominated assets. But if ever China decides to make a change in their policy and start moving out of their dollar assets dollar can easily crash. This fact is very much explained in this section. If you get a chance read the entire article on US Public Debt (in the link above).

By the way, everybody knows that China and US have huge ideological differences. If ever China and US get involved in a military conflict China can easily destroy dollar value which in turn would bring lot of huge economic problems to the world including China and of course US. China is becoming stronger every day and their military power is increasing. The question really is when will China start using its military in a big way to become a super power like US. When that day comes the world is sure to go though a major change and that will eventually lead to change in the value of US Dollar.

Also one should read this section: Long-term risks to financial health of federal government The expenditure of US govt (for expenses like Social Security, Medicare, interest) etc has been increasing at a faster pace than their revenue generation. Lot of Economists believe that this situation if unchecked can lead to bankruptcy of US Govt similar to the Russian Financial Crisis of 1998.

Another interesting article is on Seigniorage where Govt can make profit out of printing money. US Govt has been practicing Seigniorage and this puts lot of downward pressure on US dollar value.