Eliminating poppy agriculture was seen as a way of fighting corrupting and cutting insurgents' ties to the drug trade when the effort began in 2002, The Washington Post reported Sunday.
Rural farmers have long depended on the flower from which opium is made for their livelihoods and resisted campaigns to present them alternative forms of income.
An elder in Helmand province, Hajji Sha Wali, said poppy farmers in the region were once receptive to such ideas.
"They told us they would give us alternatives, build bridges for us, but they didn't keep their promises," he said. While many Afghans are opposed to the drug trade, "people are very impoverished, and costs are rising every day. Meanwhile, the armed opposition forces are getting people to plant poppy so they can make money from it."
For the first time in several years, the Afghan army this year did not provide security to eradication teams, effectively ending the effort to wipe out the drug crops.
Law enforcement officials and counter-narcotics experts say the opium trade is booming, with demand undiminished and insurgents becoming ever more involved in its production and distribution.
Afghan politicians are reluctant to attack the drug trade because many of them rely on its proceeds as contributions from foreign governments shrivel, said Jean-Luc Lemahieu, head of the United Nations' Office on Drugs and Crime in Afghanistan.
In July, a Pentagon progress report on Afghanistan said this year's poppy harvest was expected to be "considerably" bigger than that of 2012. It added that demand remained high and "insurgent penetration of that market is extensive and expanding."
Getting to the roots of the drug problem could take a decade and require greater cooperation from Afghanistan's neighbors, said Haroon Rashid Sherzad, Afghanistan's deputy counternarcotics minister.
"They should understand that the drug economy is fueling terrorism, destabilizing the region and the global village," he said. "It is vanishing the achievements of the past 10 years."