There is a reason why every fiat currency in the history of the world has eventually failed. At some point, those issuing fiat currencies always find themselves giving in to the temptation to wildly print more money. Sometimes, the motivation for doing this is good. When an economy is really struggling, those that have been entrusted with the management of that economy can easily fall for the lie that things would be better if people just had "more money". Today, the Federal Reserve finds itself faced with a scenario that is very similar to what the Weimar Republic was facing...
http://theeconomiccollapseblog.com/archives/quantitative-easing-worked-for-the-weimar-republic-for-a-little-while-too