Assume, for the sake of argument, you’re a terrorist, bent on carrying out an act of major destruction and your weapon of choice is a truck bomb.

Further suppose that to accomplish your nefarious goal you walk into a fertilizer dealership where no one knows you and say, “I need to do some fertilizing and I’d like a couple tons of ammonium nitrate. To go, please.”

What are the chances the dealer would start filling your truck with AN?

I’d bet, given Oklahoma City and Bali and Iraq and dozens of other terrorist incidents involving fertilizer bombs, the likelihood of getting a truckload of ammonium nitrate from a dealer who doesn’t know you would be somewhat equivalent to winning the Powerball lottery.

I’d be surprised if there’s a fertilizer dealer anywhere in this country who doesn’t now make it a point to know exactly who’s buying AN in any significant amount.

There was much ado in the media recently about reports “an unidentified man” was trying to buy between 500 and 1,000 metric tons of ammonium nitrate (the Oklahoma City federal building was destroyed by just two tons). The Bureau of Alcohol, Tobacco, Firearms, and Explosives gave the rumor enough credence that they were asking fertilizer/explosives dealers to report any inquiries about large amounts of AN.

But 500 to 1,000 metric tons? How many 18-wheelers would it take to cart that away? And what dealer in his right mind would not immediately see a forest of warning flags?

The day when a Tim McVeigh can back up a Ryder truck and get two tons of AN is no more. That ship has sailed.

The Fertilizer Institute and its members nationwide have joined ATF and other organizations in a campaign to secure ammonium nitrate against criminal use. It’s called “America’s Security Begins With You” and has the support of the Department of Homeland Security.

Everyone who handles AN is urged to maintain records of all sales and alert law enforcement of any suspicious inquiries or purchase attempts via a toll-free hotline. Sellers are also asked to require all purchasers to furnish government-issued photo ID and to verify both their identity and address.

Attempts are under way in Congress to make such procedures mandatory. Rep. Maurice Hinchey, D-N.Y., has introduced legislation, the Ammonium Nitrate Security Act, to implement National Academy of Sciences recommendations, requiring (1) that sellers of detonable nitrate fertilizers be licensed and that purchasers obtain permits, (2) that facilities and individuals storing nitrate fertilizers follow safety and security regulations established by ATF; and (3) that any theft or loss of such materials from manufacturers, distributors, or retailers be immediately reported to ATF.

“Licensing and permitting is the only way to keep this potentially deadly substance out of the hands of would-be terrorists,” Hinchey says. “The fertilizer industry has made commendable efforts to secure its products against use by criminals and terrorists, but given the current threats we face, this issue is too important to be left to voluntary measures.”

The Fertilizer Institute says the measure “is a first step in a welcome dialogue on this issue.”