Story highlights The United States still has more than 3,000 tons of chemical weapons

It agreed to destroy all of its stockpile in the 1990s

It expects the remaining 10% to be eliminated in another decade

Syria has a year to get rid of its estimated 1,000 tons of chemical weapons

Syria has been given a year to eliminate its chemical weapons arsenal, or face the threat of a U.S. military strike. Yet it may come as a surprise that the United States has still not destroyed all of its massive supply of deadly nerve agents.

In fact, neither has Russia. Both Washington and Moscow signed the Chemical Weapons Convention of the 1990s, which forbid the use, production and stockpiling of chemical weapons.

And both countries missed the convention's extended deadline last year to destroy all of their chemical weapons.

"Certain states have not observed the deadline, which was April 2012, for destroying their chemical weapons," the Nobel committee noted in its official announcement of the coveted peace prize. "This applies especially to the USA and Russia."

The United States estimates it will be at least another decade before it completes destruction of the remaining 10% of its chemical weapons, estimated at more than 3,100 tons. Russia has more than five times that amount left to destroy, according to the OPCW. While it's unclear exactly how many chemical weapons Syria has, U.S. intelligence and other estimates put its chemical weapons stockpile at about 1,000 tons stored in dozens of sites.

The United Nations has given Syria until mid-2014 to destroy that arsenal and U.N. weapons inspectors have expressed optimism that this deadline can be reached , despite having to dart in and out of battle zones amid Syria's bloody civil war.

The storage igloos at the Utah depot where munitions were stored and the destruction facility, in the background.

Wade Mathews, who once worked on the U.S. project to destroy its chemical stockpile, isn't so sure that Syria can meet that deadline. He said the U.S. effort took billions of dollars, the cooperation of many levels of government -- including the military -- and a safe environment to make sure the destruction was done safely.

"We had a coordinated effort, we had a government that insisted that it be done safely and that the community was protected," said Mathews, who now works with the Tooele County emergency management team, which makes sure the Utah community is aware of the project. "I don't think those things are in place in Syria."

Mathews briefly worked at the Desert Army Chemical Depot in Tooele, a desert town bracketed by mountains outside of Salt Lake City where 43% of the nation's chemical weapons were once stored. The rest was stored at eight other sites around the country.

The weapons were first warehoused at the Tooele facility in 1942, during World War II, and grew over time. At one point, the United States once housed the majority of its chemical arsenal --13,000 tons -- and a million munitions at the facility.

Tooele was chosen because military leaders figured Japanese warplanes could hit the West Coast but not fly over the mountains to Utah without refueling, said Richard Trujillo, who spent 40 years working at the facility.

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"There was mustard gas originally ... a lot of smoke-type bombs, smoke pods," Trujillo recalled. Then, in the 1950s, a lot of nerve gas was transported to the facility, he said.

Eventually, the United States signed the international chemical treaty in the 1990s and got serious about getting rid of the chemicals in a way that would not harm the environment or the people working at the plant or living in the area. While the process was slow and expensive, Trujillo said there was not a single casualty despite the volatility of some of the chemicals.

"You know the whole task is nothing short of miraculous in my mind," Trujillo said. "And I was part of it."

Today there are no weapons at the Tooele facility. The process of safely getting rid of these chemicals and munitions took 16 years, and was finally completed last year. Workers there will soon begin the process of dismantling the plants needed to do the job.

Yet, there are still more than 3,000 tons of chemical weapons left in the United States, stored at two remaining facilities at Pueblo, Colorado, and Bluegrass, Kentucky. The majority is in Pueblo, where officials plan to start in 2015 destroying 2,600 tons of mustard blister chemicals stored in projectiles in liquid form. The process is expected to take four years.

At the Bluegrass plant outside Lexington, Kentucky, there are 523 tons of mustard agent, VX and sarin nerve agents. Officials predict the job of destroying that arsenal, which is slated to start in 2020, will be completed in 2023.

The world's attention turned to Syria's chemical weapons stockpile after the United States and other countries accused Syria of using chemical weapons in an August 21 attack outside Damascus, a strike Washington says killed more than 1,400 people -- including many women and children. Syria denies the accusation and says its own troops have faced poison gas attacks by rebel forces in the civil war that began in 2011.

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Photos: Photos: Suspected chemical attack in Syria Photos: Photos: Suspected chemical attack in Syria Suspected chemical attack in Syria – A convoy of inspectors from the Organisation for the Prohibition of Chemical Weapons prepares to cross into Syria at the Lebanese border crossing point of Masnaa on Tuesday, October 1. Inspectors from the Netherlands-based watchdog arrived in Syria to begin their complex mission of finding, dismantling and ultimately destroying Syria's chemical weapons arsenal. Hide Caption 1 of 17 Photos: Photos: Suspected chemical attack in Syria Suspected chemical attack in Syria – The U.N. Security Council votes to approve a resolution that will require Syria to give up its chemical weapons during a meeting on Friday, September 27. The vote came after assertions by the United States and other Western nations that the Syrian government used chemical weapons in an August 21 attack outside Damascus that U.S. officials estimate killed 1,400 people. Hide Caption 2 of 17 Photos: Photos: Suspected chemical attack in Syria Suspected chemical attack in Syria – U.S. Secretary of State John Kerry said the world community was imposing a binding obligation on the government of Syrian President Bashar al-Assad to get rid of its chemical weapons stockpile. Hide Caption 3 of 17 Photos: Photos: Suspected chemical attack in Syria Suspected chemical attack in Syria – A man mourns over the bodies of those killed in a suspected chemical weapon attack in a suburb of Damascus, Syria, on Wednesday, August 21. Syrian rebels said poisonous gas rained down from rockets, but authorities have denied the allegations that they used chemical weapons and accused the opposition of staging the attacks. U.S. officials, however, said there were "strong indications" that there was a chemical weapons attack by the government. Hide Caption 4 of 17 Photos: Photos: Suspected chemical attack in Syria Hide Caption 5 of 17 Photos: Photos: Suspected chemical attack in Syria Suspected chemical attack in Syria – People attend to the victims of the attack on August 21 in Damascus. British intelligence said at least 350 people died, while rebel leaders have put the death toll at more than 1,300. Hide Caption 6 of 17 Photos: Photos: Suspected chemical attack in Syria Suspected chemical attack in Syria – Constricted pupils was listed as a symptom in victims of the alleged attack on August 21. Hide Caption 7 of 17 Photos: Photos: Suspected chemical attack in Syria Suspected chemical attack in Syria – Victims of the attack are laid in the back of a truck in the Hamoria area of Damascus on August 21. Hide Caption 8 of 17 Photos: Photos: Suspected chemical attack in Syria Suspected chemical attack in Syria – A young survivor takes shelter in a mosque in the Duma neighborhood of Damascus on August 21. Hide Caption 9 of 17 Photos: Photos: Suspected chemical attack in Syria Suspected chemical attack in Syria – Victims are buried in a suburb of Damascus on August 21. Hide Caption 10 of 17 Photos: Photos: Suspected chemical attack in Syria Suspected chemical attack in Syria – People search for the dead to collect samples to check for chemical weapon use in the Zamalka area of Syria on Thursday, August 22. Hide Caption 11 of 17 Photos: Photos: Suspected chemical attack in Syria Suspected chemical attack in Syria – A group of young Salafists chants and waves black flags during a protest against the Egyptian and Syria regimes in the southern Gaza Strip on August 22. Hide Caption 12 of 17 Photos: Photos: Suspected chemical attack in Syria Suspected chemical attack in Syria – A young woman holds a Syrian revolution flag and a candle during a protest of President Bashar al-Assad in front of the U.N. headquarters in Gaza City on Friday, August 23. U.N. Secretary-General Ban Ki-moon intends to conduct a "thorough, impartial and prompt investigation" into the alleged chemical weapons attack in Syria. Hide Caption 13 of 17 Photos: Photos: Suspected chemical attack in Syria Suspected chemical attack in Syria – Pigeons' bodies litter the ground in the Damascus suburbs of Arbeen on Saturday, August 24. Hide Caption 14 of 17 Photos: Photos: Suspected chemical attack in Syria Suspected chemical attack in Syria – Syrian soldiers are deployed in the Jobar neighborhood of Damascus on August 24. Hide Caption 15 of 17 Photos: Photos: Suspected chemical attack in Syria Suspected chemical attack in Syria – Syrian President Bashar al-Assad speaks with the Russian newspaper Izvestia in Damascus, Syria, on Monday, August 26. He told the newspaper that Western accusations that the Syrian government used chemical weapons are an insult to common sense. Hide Caption 16 of 17 Photos: Photos: Suspected chemical attack in Syria Suspected chemical attack in Syria – Representatives of Arab countries discuss Syria at the Arab League headquarters in Cairo, Egypt, on Tuesday, August 27. President al-Assad vowed to defend his country against any outside attack. "The threats of launching an aggression against Syria will increase its commitments," and "Syria will defend itself against any aggression," he said, according to Syrian state TV. Hide Caption 17 of 17

Last month, the U.N. Security Council later voted unanimously to require Syria to eliminate its arsenal of chemical weapons or face consequences. The U.N. team in Syria overseeing the destruction of Syria's chemical weapons says the Assad regime is cooperating

It's unclear how these weapons can be found, secured, and safely destroyed by next year in the middle of a protracted conflict, considering that it is expected to take the United States three years to destroy half of the chemical weapons that Syria is estimated to have -- and that's in a remote part of Kentucky with no civil war.

Asked about that, the U.S. Department of Defense told CNN in a written statement that it's "inaccurate to draw parallels between the U.S. chemical demilitarization program and the international cooperation that will be required to destroy the chemical stockpile in Syria."