In a larger sense, nobody wins in the war in Afghanistan. But Marine sergeant Brian Nelson is hoping that in one particular instance — encouraging Afghans to convert some of their crops to biofuel — everyone can win.
Marines win because they can help meet their alternative energy goals. They want to cut fuel usage by half in the next 14 years, because fuel runs are unusually vulnerable to attack. (Perhaps preferable: Not f*cking being at war in 14 years. But I digress.)
Afghans win because instead of opium poppies — which have put money in the hands of insurgents and warlords, and led to a widespread opium problem — they can switch their cash crop to biofuel-ready cotton (which has a couple other uses too; you may have heard about them from Zoe Deschanel).