5) What's classified?
Kerry, Hagel and Dempsey repeatedly responded to questions by saying they could provide more complete answers at the committee's classified meeting on Wednesday, but that didn't prevent some tidbits from emerging.
Dempsey confirmed a French assessment of Syria's chemical weapons stocks, telling Democratic Sen. Dick Durbin of Illinois that the U.S. assessment was similar.
Durbin said France concluded Syria possessed "more than 1,000 tons of chemical agents and precursor chemicals, several hundred tons of sarin, representing the bulk of their arsenal" and "the missile capability of delivering these chemical weapons in Israel, portions of Turkey, Jordan, Iraq and beyond."
On another point, Kerry stepped in after Dempsey and Hagel said they lacked details on specific figures for the estimated number of opposition fighters, telling Johnson that "you see ranges up to 80,000, 90,000, 100,000 in total opposition" and "in the tens of thousands in terms of operative active combatants."
Kerry also told his successor as U.S. senator from Massachusetts, former Rep. Ed Markey, that the United Nations was expected to take about three weeks to provide results from tests by its inspectors of the chemical weapons site in the suburbs of Damascus.