I think it is not a problem if the dollar has crashed, because there are still other currency could be an alternative trading currencies, such as the euro, yen and others. it is still a very small possibility for the time being, because the dollar is still the belle of the trading currency, the world community is still very interested in collecting dollars, while the dollar linkage with bitcoin, it is like two sides of a coin that can not be separated, mutual need and complement one another ...