Pentagon planners have been putting together military options for the president to consider in dealing with Syria's chemical weapons. Analysts say none of those scenarios is simple or straightforward - as they could involve the deployment of tens of thousands of troops, a high risk of contamination, and a likely large-scale escalation of the conflict.
The options being considered include bombing weapons sites and even the possibility of arming rebels.
In any scenario, there are no easy or quick solutions, leading Defense Department officials to proceed with extreme caution.
Defense Secretary Chuck Hagel said the U.S. has concluded with some degree of varying confidence that Syria has used chemical weapons, but cautions against any rash decisions.
"We are continuing to assess what happened, when, where. I think we should wait to get the facts before we make any judgments on what action, if any should be taken, and what kind of action," Hagel said.
Just locating the chemical weapons would be a monumental operation that could involve the deployment of hundreds of U.S. troops, who would be tasked with safeguarding the weapons and preventing contamination - a job for which they have already trained extensively in places like Iraq.
Syria's air defenses remain strong, and analysts envision a powerful and fierce reaction from Bashar al-Assad's forces.
Michael Rubin, of the American Enterprise Institute, said it could be a messy operation.
“We're not going to be able to simply secure the chemical weapons. That could take a couple of weeks and that would be if the government was cooperating with us," he said. "So, if we want to get rid of the chemical weapons, it literally means bombing them. That's going to spread a great deal of contamination.”
Another approach would be to set up a safe haven involving the enforcement of no-fly zones that would require even more resources and participation from allies - making it an even more complicated option.
With no consistent intelligence at this point, the choices remain unclear.