Murphy's Law: The Ammonium Nitrate Nightmare

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December 11, 2011: The U.S. is having a difficult time preventing the Taliban and drug gangs in Afghanistan from getting explosives. That's because of the widespread use of ammonium nitrate fertilizer, which has become the favorite bomb building material in the area. Anticipating this, two years ago, the Afghan government agreed to ban the use of ammonium nitrate and make available other (less effective) fertilizers. That program did not work out. The problem was that the terrorists only needed about 600 kg (1,320 pounds) of ammonium nitrate a day to keep their bombing campaign going. The existing smuggling network (from Pakistan) had no problem sneaking that much in. Paying locals to build and plant these bombs cost less than a million dollars a month.

The Afghan bomb makers even learned how to remove an "anti-explosive" ingredient from the fertilizer. The ammonium nitrate fertilizer produced (at only two factories) in Pakistan has calcium carbonate added to make it less explosive. But the calcium carbonate is easily removed by simple, if time consuming, procedures that the Afghan tribesmen can handle. The U.S. wants to include another additive (urea granules) to make the ammonium nitrate less explosive and more difficult to remove all additives. That really doesn't solve the problem; it just makes ammonium nitrate a little more expensive for the terrorists to use. The bomb makers have lots more to worry about than additives.

In Afghanistan, as in Iraq, the use of IEDs (Improvised Explosive devices) resulted in lots of countermeasures. In Iraq the U.S. mobilized a multi-billion dollar effort to deal with IEDs, and that paid off. New technology (jammers, robots), tactics (predictive analysis and such), equipment (better armor for vehicles and troops) and a lot of determination did the job. Gradually, IEDs became less dangerous. In 2006, it took about five IEDs to cause one coalition casualty (11 percent of them fatal) in Iraq. By 2008 it took nine IEDs per casualty (12 percent fatal). That trend has continued in Afghanistan, where it now takes over 60 IEDs to kill one foreign soldier. But the drug profits are so large and the ammonium nitrate IEDs so cheap to build and use, that these bombs keep showing up.

Foreign troops in Afghanistan are now encountering over a thousand IEDs a month. This is twice what they encountered in early 2009. About half of combat deaths are from IEDs, which is down from about 61 percent. Overall casualties in Afghanistan are down 15 percent this year. The percentage of casualties from IEDs is rapidly declining as more MRAP armored vehicles and countermeasures are moved in. Currently, over 80 percent of the IEDs encountered last month are detected before they could harm foreign troops.

There are several differences between the IEDs in Iraq and Afghanistan. These include the quality of manufacture, the skill of emplacement, and the explosives used. In Iraq there were thousands of tons of munitions and explosives scattered around the country after the 2003 invasion ended. This was the legacy of Saddam Hussein and the billions he spent on weapons during his three decades in power. The Iraqi terrorists grabbed a lot of these munitions and used them for a five year bombing campaign.

With no such abundance of leftover munitions, the Taliban had to fall back on a common local explosive, ammonium nitrate. This is a powdered fertilizer that, when mixed with diesel or fuel oil, can be exploded with a detonator. While only about 40 percent of the power as the same weight of TNT, these fertilizer bombs are effective as roadside bombs. But they are bulkier, and a slurry, usually mixed in a plastic jug or a barrel. Moreover, the fuel oil must be mixed thoroughly and in exactly the right proportion, otherwise the explosive effect is much less than expected. But the biggest problem is that if you can't get the ammonium nitrate, you have no explosives. But attempts to ban ammonium nitrate failed.

While IEDs are even less effective in Afghanistan, because they are the main cause of NATO casualties, they get a lot of media attention. In Afghanistan the enemy started off with one big disadvantage, as they didn't have the expertise or the resources of the Iraqi IED specialists. In Iraq the bombs were built and placed by one of several dozen independent gangs, each containing smaller groups of people with different skills. The Taliban IED gangs are much less skilled than those encountered in Iraq. At the same time, the equipment, techniques, and troops who neutralized the IED campaign in Iraq have been moved to Afghanistan. This is a major reason the effectiveness of Taliban IED attacks are declining so quickly.