Its called calcium ammonium nitrate, a substance with a Jekyll and Hyde nature. Used as a crop fertilizer, it helps feed people. But during the war against the Taliban, CAN produced in factories in Pakistan flowed into Afghanistan and became the primary ingredient in improvised explosive devices that killed or maimed hundreds of U.S. service members.
Three years ago, Sen. Bob Casey, D-Pennsylvania, set out to address the CAN issue and the growing number of IED casualties.
He introduced Senate Resolution 570, which called for the governments of Pakistan, Afghanistan and other Central Asian countries to better regulate the manufacture, sale, transport and use of CAN to reduce its presence in Afghanistan.
Stories of soldiers losing arms and legs motivated him to act.
The IED issue came home to Centre County last month, when State College High School graduate Adam Hartswick lost both legs to a roadside bomb in Afghanistan. Hartswick is recovering at Walter Reed National Military Medical Center in Bethesda, Md.
Those kinds of stories proliferated throughout Pennsylvania, Casey said. It seemed like every time there was a story about a soldier who was injured in Afghanistan, or killed, it had an IED connection. Its far and away the leading killer.
S.R. 570 passed unanimously. But Casey went further.
In 2011, IEDs claimed about 2,000 U.S. casualties and almost 2,400 Pakistani military personnel and civilians.
That same year, after he traveled with three other senators to Pakistan and discussed CAN with senior government officials, Casey successfully introduced an amendment to the National Defense Authorization Act.
Under the terms of the amendment, Pakistan must show that it is controlling CAN production, as well as the making of other common IED materials such as potassium chlorate, to receive some security assistance.
In addition, the Secretary of Defense must produce a report certifying Pakistans efforts on countering IEDs, as well as its progress on other security matters, such as the threat of nuclear weapons.
Though the certification report has been waived the past two years in the interest of foreign relations and national security, one breakthrough occurred in March. The Fatima Group, which makes and distributes CAN in Pakistan, agreed to halt its distribution in two western provinces that serve as main gateways into Afghanistan.
And, according to the Department of Defense, IED casualty-causing attacks on coalition forces this year have decreased 58 percent from 2012. Attacks on Afghan National Security Forces, however, have shot up 92 percent as they take the lead in operations.
Casey, who led a 2012 hearing on the tie between Pakistan and IEDs as the chairman of the Foreign Relations Subcommittee on Near Eastern and South and Central Asian Affairs, said he has learned to be cautious when assessing progress on the issue.
Improvement has come slowly, he said, but much work remains.
We have to be vigilant and continue to be determined, because the enemy will continue to make these bombs, Casey said. Its going to be challenging.
Potassium chlorate, for example, has replaced CAN this year for the first time as the leading ingredient in homemade explosives used as the main charge for IEDs, according to the DOD.
Persistent enemy networks arent the only vexing problem. The rugged, porous border between Pakistan and Afghanistan makes enforcement of exports difficult. And since CAN plays an important agricultural role in the region, it cant be banned entirely, for fear of famine.
During the 2011 visit to Pakistan, Casey said, the senators helped sway government officials by repeatedly pointing out that Pakistans citizens also suffered from IED blasts.
According to Caseys opening statement in the 2012 hearing, Pakistani Embassy reports indicated IED attacks had killed about 38,000 Pakistani civilians and about 6,400 security force members since Sept. 11, 2001.
Despite their brooding about the U.S. raid against Osama Bin Laden on their soil three months before, Pakistani officials seemed to take the IED issue seriously, Casey said.
They listened, and I think they understood the gravity of the problem, he said. We just happened to be there at a very particularly difficult time.
For Casey, a demonstration in Afghanistan crystallized the importance of limiting increasingly powerful IEDs.
Though the pretend IED that was detonated wasnt as strong as real ones, the blast impressed Casey.
Even from 100 yards away, he said, it was loud and just really disturbing to have some sense, at a great distance, of the explosive capacity of something that was nowhere near what a soldier encounters or what the enemy can produce.