So operation DIESEL, in reality, resulted in the finding and destruction of somewhere in the region of 1300kg of unprocessed opium and an a quantity of the chemicals required to process opium into heroin. A few quick sums: According to the UNODC the 'farm-gate' price for opium in Afghanistan in 2008 was $85 a kilo, and these DIESEL stockpiles were presumably not far from the Helmand farms on which they were produced. 1300 x 85 = $110,500, in other words, opium worth approximately £78,000 to the Taliban, at this point in the supply chain.
Were this 1300kg of opium to have been turned into low grade heroin (and we can reasonably suspect that this was what was going to happen), on the basis that it takes around 10kg of opium to produce 1 kg of heroin, it would have produced around 130kg. If the ‘street price’ of a kilo of heroin in the UK is estimated to be around £50- 75,000, then 130 kilos would earn you somewhere between £6.5 and £9.7 million. A very large sum of money certainly, albeit nowhere near £50 million.
It does make you wonder what drugs the MoD is on.