Since 1993, when the Drug Enforcement Administration realised that the killing of Pablo Escobar had made no impression on the price of cocaine on American streets, practically every British newspaper has run editorials urging politicians to rethink drugs policy, up to and including legalisation. Yet politicians still regard legalisation as a ‘third rail’ issue guaranteed to kill the career of anyone who so much as touches it.

Johann Hari is to be credited for writing an entertaining book that tackles all of the big questions the politicians are afraid to ask. Until 2011, Hari was a prominent young columnist for The Independent, but he resigned after admitting to plagiarism. He was also found to have pseudonymously doctored the Wikipedia profiles of several journalists who had picked up on his slapdash approach to the rules of the trade.

By way of penance, Hari set off on a three-year, 30,000-mile odyssey into the war on drugs. His discoveries startled him: not only are drugs ‘not what we think they are’, but ‘drug addiction is not what we have been told it is’ and ‘the drug war is not what