THE ingredients most likely to spark confrontation between the United States and Iran could scarcely be simpler or more combustible: a tin filled with an explosive charge and a lump of copper is all that is needed to manufacture what the US military calls an Explosively Formed Penetrator (EFP). When the device is triggered by an infrared sensor it fires a molten ball of metal at its target with sufficient speed to penetrate most American vehicles' armour. The… more