"I strongly suggest that your departments consider the trends in opium cultivation and the effectiveness of past counternarcotics efforts when planning future initiatives," Sopko wrote in a letter to Secretary of State John Kerry and Secretary of Defense Chuck Hagel, among other U.S. leaders. "The recent record-high level of poppy cultivation calls into question the long-term effectiveness and sustainability of those prior efforts."
Numerous U.S. departments contributed to the $7.6 billion in funding, including the Pentagon's Afghan Security Forces Fund and the State Department's International Narcotics Control and Law Enforcement fund.
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The failure to eradicate poppy is "due to the lack of Afghan government support for the effort," Michael Lumpkin, assistant secretary of Defense for Special Operations, wrote in a letter to Sopko.
"Poverty, corruption, the terrorism nexus to the narcotics trade, and access to alternative livelihood opportunities that provide an equal or greater profit than poppy production are all contributors to the Afghan drug problem," Lumpkin said.
"There is no silver bullet to eliminate drug cultivation or production in Afghanistan," Charles Randolph, a program coordinator at the U.S. Embassy in Kabul, wrote in a letter responding to the report.