After some difficulty last year in working with leaders of two Pakistani fertilizer factories, which produce most of the ammonium nitrate used by insurgents to make homemade explosive devices in Afghanistan, the Joint Improvised Explosive Device Defeat Organization is reporting progress in the factories' effort to curb the flow of the substance into IED-making networks, according to JIEDDO's director. Of 400,000 metric tons of ammonium nitrate the two factories produce, the Pentagon believes about 1 percent makes its way into...