For more than four decades Peru has fought its war on drugs with the backing of the United States. 

Here you have to dance at the rhythm they [cartels] play. If not, you get killed

Former port worker in El Callao

Ten of thousands of coca plants and hundreds of tonnes of cocaine have been destroyed. Despite these efforts, the United Nations now says that Peru is the most important producer of cocaine in the world. With this has come levels of corruption and violence that threatens the very fabric of the country. 

Over the past year, the battle has focused on the capital Lima's port, with criminal cartels fighting for control of the main exit route for the drug.

It is a war everyone knows can never be won, but not to fight it is un-thinkable. Sonia Medina, Peru's anti-drug prosecutor, continuously risks her life - and that of her family - to face down the narcotic cartels and end their growing grip on her country.

Globally, the supply and consumption of cocaine have gone up, while the price has gone down. Governments have spent billions of dollars fighting the scourge, while it has cost hundreds of thousands of people their lives.

Source: Al Jazeera