The US dollar is highly important in today's economy for three main reasons: the huge amount of petrodollars, the use of the dollar as the world's reserve currency, and the decision taken by US President Nixon in 1971 to end the dollar convertibility into gold.
The Petrodollar, long serving as the US leverage to encourage and facilitate USD recycling, and a steady reinvestment in US-denominated assets by the Oil exporting nations, and thus a means to steadily increase the nominal price of all USD-priced assets, just drove itself into irrelevance. A consequence of this year's dramatic drop in oil prices, the shift is likely to cause global market liquidity to fall. This decline follows years of windfalls for oil exporters such as Russia, Angola, Saudi Arabia and Nigeria. Much of that money found its way into financial markets, helping to boost asset prices and keep the cost of borrowing down, through so-called petrodollar recycling. But no more: "this year the oil producers will effectively import capital amounting to $7.6 billion.