By Peter Bergen, Nawa district, Helmand, Afghanistan If the southern Afghan province of Helmand were a country it would be the world's leading producer of opium and its derivative, heroin. More than half the world's heroin originates here -- much of it destined for the veins of junkies living in Europe. In June 2005, U.S. Drug Enforcement Agency officials and Afghan police raided the office of Sher Mohammed Akhundzada, the governor of Helmand, and found nine tons of opium in his office. He is no longer the governor. According to an unpublished threat assessment by the Afghan army of the security situation as it was this April in Afghanistan which was obtained by CNN, Helmand province had the highest percentage of territory controlled by the Taliban of any of the country's 34 provinces. Nearly 60 percent of Helmand in April was fully Taliban-controlled, and the remainder was classified as "high risk" for Taliban attacks. According to a senior Marine officer 20 percent of the Taliban in Helmand are ‘ideologues' who are not from the local area and are influenced by the Pakistan-based central command of the Taliban -- such as its leader Mullah Omar. The other 80 percent are local ‘opportunists' who are making money being paid by the Taliban to do jobs such as planting roadside bombs known as Improvised Explosive Devices (IEDs). U.S. intelligence officials estimate that the Taliban can pay approximately $300 a month to its rank-and-file soldiers. An Afghan policeman is lucky if he makes $100 a month. Since early July, some 4,500 American U.S. Marines and hundreds of Afghans soldiers have launched offensives against the Taliban in Helmand and, according to a senior U.S. Marine officer, as a result the Taliban "are on their arse, literally." The officer said that of the 13 districts in Helmand, only one is now fully controlled by the Taliban. However, they continue to maintain a persistent presence in the province and are capable of launching IED attacks at will throughout Helmand. In Dawa district, in central Helmand, Marines at a dusty, spartan base with no electricity or running water venture out on several-hour foot patrols. They move through canal-fed corn fields armed with metal detectors and a bomb-sniffing dog looking to discover and disable IEDs. The IEDs range from simple victim-operated bombs, typically pressure plate devices made from wood and springs, to more complex devices that are remotely detonated using a command wire. The corn rows that stand 10-feet high provide an ideal environment in which the IED triggermen can hide. During World War II, three percent of American combat deaths were caused by mines or booby traps. By 1967 during the Vietnam War the figure rose to nine percent. In Iraq during the latter half of 2005, IEDs were the leading cause of American combat deaths, responsible for 65 percent of all fatalities and half of all nonfatal injuries. According to Brigadier General Laurence Nicholson, who is in charge of the Marine brigade in Helmand, an astonishing 80 percent of the casualties of the Marines under his command are now caused by IEDs. Just one more statistic that helps explain why Helmand remains one of the more dangerous places on the planet. Peter Bergen, the editor of the AfPak Channel, is a senior fellow at the New America Foundation and at New York University's Center on Law and Security, and the author of The Osama bin Laden I Know: An Oral History of al Qaeda's Leader. He is a national security analyst for CNN, on whose website this was originally published.