Nixon severed the gold standard because of the Vietnam War and higher public expenditures like the Space Program. When there was a gold standard, government spending was limited to tax revenues. With the Vietnam war, taxes were going up and became unaffordable, the Americans were against the war and the rising taxes. By severing from the gold standard, governments can spend what they like by printing money out of thin air, hence why the amount of money expanded since 1970 shot up, see any graphs as the previous hundreds years of money expansion was relatively flat then surged upwards till this day. Hence why since the 1970's we all had huge inflation, inflation meaning expansion of money supply and NOT CPI or RPI as 99% of the humans believe it to be so.