It's pretty funny to look at it now as an investment , but some foreign currencies could replace the US Dollar one day. When this socialist, scumbag president of ours has finished doubling our national debt to 20 trillion in only four years (and he will not be getting a second term thank God) by redistributing the earns of the productive to the kind of people that support him (the whiners, lazy people, the uneducated, and those covetous of other people's property & assets) interests rates will skyrocket & inflation will wipe out millions of jobs. Bush doubled our debt from 5 trillion to 10 , in only 8 years. Obama has added 2.5 trillion in less than one year. It took Bush nearly 5 years to do that. Socialism is very expensive for the working guy.
Look at what socialism has done to California & New York, they are essential bankrupt States. If China & Japan stops buying our paper ( debt, T bills etc. ) our dollar will be worth 2-3 cents.