Opium cultivation is estimated to be at an all-time high in Afghanistan, despite the US spending $7.5bn to combat it.

A report released Wednesday by Washington’s Afghanistan war watchdog has found that the billions spent by the State and Defense departments on counter-narcotics since 2002 has been for nought. Opium-poppy cultivation takes up 209,000 hectares (516,230 acres) of land in Afghanistan, a 36% increase since 2012.

Drug use inside Afghanistan has spiked, according to the Special Inspector General for Afghanistan Reconstruction. About 1.3 million Afghan adults were regular drug users in 2012, up from 1 million in 2009; regular opium users grew to 230,000 in 2009 from 130,000 in 2005. The population of Afghanistan is just under 32 million.

Beyond Afghanistan’s borders, about three-quarters of the world’s illicit opium products originates from the country, which sees its poppy cultivation concentrated almost entirely in the country’s southern and western provinces. Those areas – particularly Helmand and Kandahar provinces – were where the bulk of US and UK forces were deployed during the 2010-12 troop surge.

The interdiction efforts that the US and its Afghan partners continue to perform, however, are concentrated in eastern Afghanistan and the capital of Kabul, a shift away from the areas of cultivation.