A Colombian farmer named Perea gave up growing coca, the raw material for cocaine, and switched to legal crops such as cassava and plantain after joining a government-run crop substitution scheme. However, promised financial and technical support largely failed to materialise, and poor infrastructure and flooding made it impossible to sell his legal produce, so in 2024 he resumed growing coca. His story reflects a wider pattern across Colombia, where coca cultivation has reached record levels despite years of substitution efforts, raising questions about the effectiveness of the country's anti-drug strategy.

The substitution programme, known as PNIS, was launched in 2017 following the peace deal with the Farc guerrilla group and enrolled around 100,000 families, each promised roughly 36 million Colombian pesos ($11,000; £8,000) plus agricultural support over two years. Colombia supplies an estimated 70% of the world's cocaine, and researchers note coca's practical advantages over legal crops, including quicker, more frequent harvests, easier transport and guaranteed prices, with cultivation shown to boost some local economies by up to 10%. Coca planting nationwide now exceeds 250,000 hectares, and many farmers, including Elena Hernández, say the scheme's promises were not fully honoured.