by system failure
On December 23, 1913, the then US President Woodrow Wilson puts the final signature for the so-called Federal Reserve Act. Big private banks take control of the US money supply. Since then and for 100 years until now, we live in the bankster-domination era. The only "break" of real peace and prosperity for the West since then, is perhaps the period after the WWII until the early 70s, though conflicts, dictatorships and wars were not absent.
The first big test of the new conditions was the 1929 crash. Banksters reduced the money supply to the market, eliminating competitors and leading to poverty millions of Americans. The same happened, more or less in the 2007-2008 financial crisis.
Although the Great Depression was a field test of the new conditions, the gold standard which was active at that time, had prevented "Federal" Reserve to print money at will thus loading government with more debt. The banksters could not fully control government through debt and Roosevelt, with his strong personality, managed to pass the laws he wanted, despite the war against him, giving some hope to the American people.
In 1971, Nixon ended the direct convertibility of the US dollar to gold, and as dollar became the global reserve currency, the absolute dominance of the banksters became definite.
Banks and big corporations couldn't wait. Just two years later (September 1973), they proceed to another big experiment, so big that it's still running. Through the U.S.-backed military coup in Chile that ousted the democratically-elected President Salvador Allende, they establish a 17-year dictatorship led by Augusto Pinochet. Chile became the first lab-rat of neoliberalism. Milton Friedman and the Chicago boys advise dictator Pinochet to kill the state and privatize everything. Chile was occupied by big cartels, US interests companies, people suffered from poverty and from Pinochet's cruel regime.
IMF, World Bank and other institutions, were the basic tools for the invation to other countries during the next decades, and the result was always mass destruction for the economies. Today, for the first time, a Western developed area, called eurozone, is being tested.