Hillsdale, Ind.—The level of security was chilling.
Just entering the site required getting past armed guards and a heavily fortified perimeter. Before we could enter the critical facilities, we first had to attend a safety class. Then, we had to don protective gear including a gas mask and a pouch containing an atropine injection kit to use on ourselves if something went wrong.
The year was 1997. The United States had just ratified an international chemical weapons treaty as the world worried about Saddam Hussein's chemical stash. Attention inevitably turned to the much larger arsenals in the U.S. and the former Soviet Union. That is what brought CNBC to the Newport Chemical Depot in rural western Indiana—at the time, one of the deadliest places on earth. A single drop of the substance stored there could kill an adult in minutes.
Fast forward to today.
You still have to pass through a gate to enter the site, but that is because most of it is vacant. Rows of corn grow where buildings containing hundreds of tons of deadly VX nerve agent once stood. Eight concrete and steel bunkers where the chemicals were moved after 9/11 still stand, but they are empty and available for rent.
"We have the availability of 200 megawatts of electricity; we are between two interstates, 70 and 74, on a four-lane highway 63. We have had a lot of interest from companies that really need this kind of a site," said Bill Laubernds, executive director of the Newport Chemical Depot Reuse Authority, which is marketing the 11-square-mile site as the Vermillion Rise Mega Park.
For prospective tenants worried about any leftovers, the Pentagon offers a free cleanup warranty in case any hazardous chemicals are found.
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The snapshots of the site in 1997 and today belie a long and difficult process that officials and experts say is proof that eliminating chemical weapons in Syria—which is supposed to be done by mid-2014 under a framework agreement between the U.S. and Russia—is much easier said than done.
Syrian President Bashar Assad suggested as much in an interview with Fox News on Sept. 18. "I think it's a very complicated operation technically, and it needs a lot of money. Some have estimated about a billion for the Syrian stockpile," Assad said.
He also questioned the feasibility of destroying the stockpile in a matter of months as called for under the agreement. "It needs a year, maybe a little bit less or a little bit more," he said.
Based on the U.S. experience, he may not be far off. The Defense Department has spent an estimated $40 billion and counting on chemical weapons destruction since 1997. The Newport depot held about 4 percent of the original stockpile.
"It is complicated, it needs a lot of coordination to do it safely and it is a challenging effort," Laubernds said.
In the case of Newport, the process actually dates back to 1969, during the height of the Vietnam War, when President Richard Nixon unilaterally renounced the first use of chemical weapons by the United States. "By the examples we set here today, we hope to contribute to an atmosphere of peace and understanding between all nations," Nixon said.
Immediately, 1,000 tons of VX nerve agent—all of which was manufactured at Newport—essentially became trapped at the facility. The depot's mission changed from maintaining the stockpile and keeping it ready for battle to safely storing it, perhaps indefinitely.
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After the U.S. formally agreed in 1997 to destroy its 30,000-ton chemical arsenal, Newport's mission changed again, becoming a site for disposal of the deadly chemicals. Various methods were considered, including incinerating the chemicals. Ultimately, they settled on a chemical neutralization process.
Not until 2008—11 years after our visit and U.S. ratification of the chemical weapons ban—was the last of the VX eliminated. The site was formally decommissioned in 2010, more than 40 years after President Nixon's declaration. And Laubernds notes that in contrast to what might take place in war-torn Syria, the process in Newport was easily controlled.
"In our case the agent was not weaponized, not loaded into weapons. It was in canisters so the canisters could be moved to a processing plant and it could be neutralized at that plant in a controlled situation."
Experts say the task in Syria could make the lengthy U.S. process look like child's play.
"It's very difficult to see how a process like that is going to work in the middle of a war zone," said Faiza Patel, a former senior policy officer at the Organization for the Prohibition of Chemical Weapons in an interview with NBC News earlier this month.
"It's a process that is very complicated and quite challenging to manage, even in normal circumstances," said Patel, who is now co-director of the Brennan Center for Justice's Liberty and National Security Program at New York University.
Even now, a sizeable portion of the U.S. chemical arsenal remains. The nation still has approximately 3,134 tons—a little more than 10 percent of the original stockpile, according to the Army's Chemical Materials Agency.
Most of the cache consists of blister agents like mustard gas, stored at a heavily guarded facility in Pueblo, Colo. Around 500 tons of weaponized nerve agents, including VX and Sarin in rockets and warheads, is stored at a facility in Bluegrass, Ky.
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The U.S. has estimated it will be 2023—16 years after the deadline under the treaty—before the rest of the materials are destroyed.
Russia, which had the largest chemical arsenal on earth at around 40,000 tons, still has around 17,000 tons including Sarin, according to the Organization for the Prohibition of Chemical Weapons, which is overseeing the destruction process worldwide. Russia has estimated it will destroy the rest of its stockpile by 2020.
In all, about 81 percent of the world's declared stockpile of 71,196 metric tons of chemical agents has been verifiably destroyed, according to the OPCW.
In Indiana, where they have attracted four companies at the Vermillion Rise Mega Park but still have thousands of acres available, they hope their experience might offer some lessons to speed up the process in Syria.
"I think that those of us that have worked in this area think it is the right thing to do and all the effort is worthwhile, but it is not something that could be done quickly or could be done without a lot of thought given to it," Laubernds said.
—By CNBC's Scott Cohn. Follow him on Twitter @ScottCohnCNBC