Too many ignorant people these days. If US$ collapses like the way MtGox did (and, by the way, you ALL know that MtGox was a fraud, right?), then you will see economic calamity the world has never seen before. There are NO other currencies that can take the place of US$. Euro comes close but it still cannot fulfull the role of the World's reserve currency. Do you want China's Yuan/Renminbi to replace the US$? Please, people. China will take the mantle of the Pax Americana soon enough. Pax Chinois, anyone?
I realize the time scale is much larger. Mount gox was the standard in the bitcoin sphere for a couple years- the dollar for 70 years. The Mt. Gox failure played out over several months, from the first signs to the final shutdown, which was accompanied by a decline on the exchange. Mt. Gox also abused their position as the dominant force in bitcoin trading to take advantage of the people they were dealing with.
China's economy is so tied to the US economy- and even the EU, another main market for Chinese exports, is totally dependent on the US as an export market- if the US economy truly collapsed, China would go with it, because the EU would collapse and the Chinese government too, as a result. A collapse of the Chinese economy- imagine 40% unemployment due to lack of demand for exports, would probably result in a popular uprising, possibly enable local uprisings in Tibet and Xinjiang, and result in a redrawing of boundaries in China.
The US is specialized as the military/police force of the planet. The security that maintains the stability of the international system allows the corrupt regimes of every nation to profit- this security is why Europe can have such an extensive social system, without having to worry about defending themselves. This public service, whether you want it or not, is what is really backing the US dollar, and why it can be expanded so much. This is why the US can run a perpetual trade deficit.
