For most of the 1990s Peru was the world’s main producer of coca, but the country’s crop has shrunk by two thirds over five years. Output plummeted after the government gave orders to shoot down aircraft heading for refining plants in Colombia. The decline of the Shining Path Maoist guerrillas also made it easier for authorities to uproot crops, while the US has spent $60m on encouraging alternatives, such as coffee. But sceptics say a recovery in the price of Peruvian coca, and the development of new export routes, show the drug barons could bounce back.