assadYouTube/Paul Romm

U.S. Defense Secretary Leon Panetta said "intelligence we have raises serious concerns" that Syrian President Bashar al-Assad may be prepared to use sarin gas in the country, and U.S. officials say that even the threat of chemical weapon use justifies outside military action.

But on Friday UN Secretary General Ban Ki-Moon corroborated the vehement denials of the Assad regime when he said there are no confirmed reports that Assad is preparing to use chemical weapons

The "threat" of weapons of mass destruction (WMDs) — nuclear, biological, or chemical — is real, but it can also be leveraged as a tactical move to hasten the ouster of an unwanted ruler (e.g. Saddam Hussein in Iraq).

The deployment chemical weapons is primarily deterred by the certainty of widespread and indiscriminate destruction, History provides insight into how devastating WMDs can be to all sides and why the international community is proactive about neutralizing that threat. 

To grasp the affect of chemical agents released into the atmosphere, look no further than the devastating meltdown of the Fukushima Daiichi nuclear plant in March 2011 after a tsunami hit Japan. 

The worldwide radiation sensor stations operated Comprehensive Test Ban Treaty Organization (CTBTO) found that the radioactive cloud of cesium-137, cesium-135 and iodine-131 crossed North America nine days after the accident and three days later "it was clear that the cloud had reached Europe” when a station in Iceland picked up radioactive materials.fukushima

After two weeks, according to the CTBTO, traces from the Fukushima accident were "detectable all across the northern hemisphere.”

It follows that the radiation released by the atomic bombs drops on Hiroshima and Nagasaki in 1945 also caught the Pacific jet stream and spread across the Northern Hemisphere.

The same principle of airflow applies for chemical WMDs: the area affected depends upon the topography and the weather conditions (in addition to the type and amount of the chemical agent and the means of dispersal).

In World War I poison gas was arguably the most feared of all weapons as several countries released more than 1.3 million tons of chemical agents — ranging from simple tear gas to mustard gas — and killed 90,000 men. The gas, released in open air, spread with the speed and direction of the wind while the concentration of the chemical diminished as it traveled away from the source.

By World War II Nazi Germany had developed deadlier gasses and then took air out of the equation by releasing nerve agents in gas chambers. The effect was catastrophic — the largest chambers could kill 2,000 people at once — since the concentration of chemicals is highest in small spaces.

In this way history — including the more recent example of Iraq causing 60,000 chemical weapons casualties in their war with Iran — informs why the U.S. would be aggressively proactive about concerns of WMDs in Syria.

And in this case there is the added danger of Syria's chemical WMDs falling into the hands of extremists who would hesitate much less before wreaking chemical havoc on a part of the world.

On the other hand, the past also gives credence to Syria's insistence that its not crazy enough to deploy WMDs on its own people.

"Syria stresses again, for the tenth, the hundredth time, that if we had such weapons, they would not be used against its people," Syrian Deputy Foreign minister Faisal Maqdad said Thursday. "We would not commit suicide."