U.S. plans for possibility that Assad could lose control of chemical arms cache As Bashar al-Assad's hold on power steadily weakens, U.S. officials are increasingly worried that Syria's weapons of mass destruction could fall into the hands of Islamist extremists, rogue generals or other uncontrollable factions. Last week, fighters from a group that the Obama administration has branded a terrorist organization were among rebels who seized the Sheik Suleiman military base near Aleppo, where research on chemical weapons had been conducted. Rebels are also closing in on another base near Aleppo, known as Safirah, which has served as a major production center for chemical munitions, according to U.S. officials and analysts. It's hard to appreciate just how much the U.S. stands out on firearms until you look at these comparative charts. Americans are 20 times as likely to be killed by a gun than is someone from another developed country. What happens when countries have fewer guns? Thousands of Americans, including those at Sandy Hook Elementary, are killed by guns every year. Japan has almost zero gun-related deaths, but it came at a cost. The opposition Free Syrian Army said it did not find any chemical weapons at the first installation. But the developments have fanned fears that even if Assad does not attack his own people with chemical weapons, he is on the verge of losing control of his formidable arsenal. A former Syrian general who once led the army's chemical weapons training program said the main storage sites for mustard gas and nerve agents are supposed to be guarded by thousands of Syrian soldiers, but he predicted that they would be easily overrun. "They're not secure," retired Maj. Gen. Adnan Silou, who defected to the opposition in June, said in an interview near Turkey's border with Syria. Probably anyone from the Free Syrian Army or any Islamic extremist group could take them over. President Obama and other leaders have warned Assad not to use chemical weapons, calling that a "red line" that would force them to take military action. But the White House has been vague about whether and how it would respond if Assad is toppled and Syria's chemical weapons are left unprotected or end up in the hands of anti-American insurgents. The Pentagon has drawn up plans for responding to possible scenarios involving Syria's chemical munitions, Defense Secretary Leon E. Panetta said Friday during a visit to Incirlik Air Base in Turkey, about 60 miles from the Syrian border. He declined to give details. Defense officials, however, said in interviews that they have been updating their contingency plans in recent weeks as chaos has overtaken Syria. They said they are working closely with Israel, Turkey, Jordan and NATO allies to monitor dozens of sites where Syria is suspected of keeping chemical weapons and to coordinate options to intervene if necessary. Pentagon officials have described their contingency planning to members of Congress in classified briefings. In public, military officials have indicated that they are preparing for potential joint operations with the Jordanian and Turkish armed forces, while sharing intelligence with Israel. U.S. officials have also sought to enlist the cooperation of Russia, which has a close military relationship with Syria and helped develop its chemical weapons program decades ago. Meanwhile, the U.S. government and some European allies have hired private contractors to train Syrian rebels in how to monitor and secure chemical weapons sites should Assad abandon or lose control of any of his stocks, according to CNN. A State Department spokeswoman declined to comment on the report.