“In one of his most influential essays, Friedman articulated contemporary capitalism's core tactical nostrum, what I have come to understand as "the shock doctrine". He observed that "only a crisis - actual or perceived - produces real change". When that crisis occurs, the actions taken depend on the ideas that are lying around. Some people stockpile canned goods and water in preparation for major disasters; Friedmanites stockpile free-market ideas. And once a crisis has struck, the University of Chicago professor was convinced that it was crucial to act swiftly, to impose rapid and irreversible change before the crisis-racked society slipped back into the "tyranny of the status quo".

A variation on Machiavelli's advice that "injuries" should be inflicted "all at once", this is one of Friedman's most lasting legacies. Friedman first learned how to exploit a shock or crisis in the mid-70s, when he advised the dictator General Augusto Pinochet. Not only were Chileans in a state of shock after Pinochet's violent coup, but the country was also traumatised by hyperinflation. Friedman advised Pinochet to impose a rapid-fire transformation of the economy - tax cuts, free trade, privatised services, cuts to social spending and deregulation. It was the most extreme capitalist makeover ever attempted anywhere, and it became known as a "Chicago School" revolution, as so many of Pinochet's economists had studied under Friedman there. Friedman coined a phrase for this painful tactic: economic "shock treatment". In the decades since, whenever governments have imposed sweeping free-market programs, the all-at-once shock treatment, or "shock therapy", has been the method of choice.”

Naomi Klein, The Shock Doctrine