U.S. Intelligence on Sarin...With a Grain of Salt DoD photo by Erin A. Kirk-Cuomo Defense Secretary Chuck Hagel tells the world Thursday in Abu Dhabi that the U.S. now believes Syria has used chemical weapons in its civil war. The U.S. intelligence community believes "with some degree of varying confidence" that Syrian dictator Bashar Assad's forces have used chemical weapons, Defense Secretary Chuck Hagel said Thursday. "Some degree of varying confidence" is a loophole big enough to fly a cruise missile through. "Is he a little bit pregnant or not?" asks retired Marine general Anthony Zinni, who ran U.S. operations in that part of the world from 1997 to 2000. The trouble with statements like that is you can get drawn in to military operations. MORE: The Thick Red Line: White House Cautious on Chemical Weapons Use in Syria The Israelis seem much more confident than the Americans that the Syrian government has recently used small amounts of chemical weapons, including sarin, against rebels in its two-year-old civil war. "The very fact that they have used chemical weapons without any appropriate reaction, is a very worrying development," General Itai Brun, head of research for Israeli military intelligence, said earlier this week. It might signal that this is legitimate. The latest U.S. intelligence assessment, which meshes with similar British and French reckonings, isn't tantamount to proof, Miguel Rodriguez, the director of the White House office of legislative affairs, told Congress in a letter Thursday. The Administration, he added, is "pressing for a comprehensive United Nations investigation that can credibly evaluate the evidence and establish what took place." "We need to know the full story," Hagel told reporters in the Persian Gulf emirate of Abu Dhabi, "and get it right." He added that "any use of chemical weapons in Syria would very likely have been originated with the Assad regime." But despite such nuance, some lawmakers were ready for action. They declared that the Syrian government has now crossed a threshold set by President Obama. "It is clear that red lines have been crossed," Senator Dianne Feinstein, D-Calif., chairman of the intelligence committee. Action must be taken to prevent larger-scale use. Last August, Obama warned "that a red line for us is we start seeing a whole bunch of chemical weapons moving around or being utilized. But history would suggest skepticism about such intelligence reports: The Gulf of Tonkin, Aug. 4, 1964: The U.S. went to war against North Vietnam on the basis of a false report that the warships USS Maddox and USS Turner Joy came under attack by the North Vietnamese navy. Perhaps a million people, largely civilians, died in the war, including more than 58,000 U.S. troops. The Al-Shifa pharmaceutical plant, Aug. 20, 1998: the U.S. destroyed this Sudanese factory with cruise missiles in retaliation for a pair of bombings of U.S. embassies in Africa two weeks earlier. The Clinton Administration said it had evidence of chemical-weapons production at the facility, and that it had ties to Osama bin Laden. Both conclusions, later investigations concluded, were likely erroneous. One person died in the attack; thousands more died for lack of medicines that the factory had been manufacturing before it was bombed. Operation Desert Fox, Dec. 16-19, 1998: The U.S. and Britain launched a four-day bombing campaign against assorted targets across Iraq suspected of housing Saddam Hussein's weapons of mass destruction. Because there was no way of knowing where the easily-hidden infrastructure needed to brew biological and chemical weapons was, U.S. military officials said the bombing's modest goal was simply to "degrade" his WMD program. But there were apparently no such weapons to be degraded. Up to 2,000 Iraqis died in the attacks. Operation Iraq Freedom, 2003-2011: As the second U.S. war with Saddam Hussein made clear, all evidence shows the Iraqi dictator got rid of his stockpiles of WMD after his defeat in the 1991 Gulf War. More than 100,000 Iraqis, most of them civilians, are believed to have been killed in the war, along with nearly 4,500 U.S. troops. It's Desert Fox that looms as the most likely template for any military action the Obama Administration might take against Syria. The Pentagon has told the White House that it would require about 75,000 troops to secure Syria's chemical weapons, which isn't likely to happen. That leaves air strikes of limited duration as the most plausible way to destroy Syria's chemical weapons and punish the Assad regime for their alleged use. But that isn't as easy as it might sound. Zinni was the four-star general in charge during Desert Fox, and he doesn't recall it fondly. "There wasn't a single WMD target on the [target] list," he says of the hundreds of strikes he oversaw. They were all potential dual-use - like pesticide plants. That's when I began having doubts about an ongoing Iraqi [WMD] program. Beyond that, any military action to take out Syria's chemical arsenal risks spewing plumes of the deadly agents and killing innocents in the way. "Hitting chemical-weapons storage areas," Zinni observes, "sends those chemical weapons somewhere." Israeli officials say the Americans are poised to attack, and could act within hours, if radical Islamists among the Syrian rebels appear to be on the verge of grabbing some of Assad's chemical weapons. "This is a trial balloon," an Israeli intelligence official says of Damascus" alleged use of chemical weapons. If the West doesn't react, maybe they will use it larger amounts. Obama finds himself in a pickle: if he does nothing, some will say Assad is pushing him around. If he orders an attack, he's likely only to degrade, not destroy, Syria's chemical weapons. Assuming, of course, that U.S. intelligence knows where they are. With reporting by Aaron Klein/Jerusalem