Washington (CNN) -- Secretary of State John Kerry, Defense Secretary Chuck Hagel and Joint Chiefs of Staff Chairman Gen. Martin Dempsey answered questions for 3 ½ hours on Tuesday at the first congressional hearing on President Barack Obama's request for authorization to launch a military strike against Syria over chemical weapons.
The hearing by the Senate Foreign Relations Committee, which Kerry used to chair, covered a range of issues about the proposed U.S. military response raised by legislators and people across the country. Here are five things we learned from it:
1) Proposed Senate resolution
The top Democrat and Republican on the Senate Foreign Relations Committee worked out a joint proposal for authorizing military action in Syria.
Democrat Robert Menendez, chairman of the panel, said he and Bob Corker, its ranking member, believe the plan "reflects the will and concerns of Democrats and Republicans alike."
The proposal, announced following the hearing, would give Obama "the authority he needs to deploy force" while assuring that any action would be "narrow and focused, limited in time," and assures that "the armed forces" would not be used for combat operations in Syria.
Separately, multiple Democratic sources told CNN Chief Congressional Correspondent Dana Bash the bill limits the authorization to 60 days with an option for an additional 30-day deadline. The proposal would dictate that there would be no American combat troops on the ground but would leave an option for a rescue mission. The deal would also press the president to release a diplomatic plan for Syria within 30 days of the authorization.
Menendez said he would hold a committee meeting on Wednesday to consider the proposal.
2) Whose red line is it?
A major Republican criticism of Obama before the hearing was that the president brought on the problem by declaring a red line for a U.S. response if Syria used chemical weapons. That accusation increased in recent days, but leaders from both parties sought to eradicate it on Tuesday.
"Now, some have tried to suggest that the debate we're having today is about President Obama's red line," Kerry said at one point. "I could not more forcefully state that is just plain and simply wrong. This debate is about the world's red line. It's about humanity's red line. And it's a red line that anyone with a conscience ought to draw."
House Majority Leader Eric Cantor, a Virginia Republican, also challenged the criticism that Obama set the red line.
"The United States' broader policy goal, as articulated by the president, is that Assad should go, and President Obama's red line is consistent with that goal and with the goal of deterring the use of weapons of mass destruction," Cantor said in a statement. "It is the type of red line virtually any American president would draw."
3) What happens after?
The main question for skeptics who are crucial to win support for military force, as opposed to outright opponents certain to vote "no", is how does the United States prevent an escalating conflict that could lead to full American involvement in Syria's civil war.
Kerry stumbled a few times in answering multiple questions about this, initially rejecting language in a resolution that ruled out any chance for U.S. ground troops.
He provided fodder to critics by acknowledging the possibility of ground forces to secure chemical weapons if the regime of Bashar al-Assad collapsed and to prevent stockpiles from falling into the hands of extremists. Kerry later insisted there was no chance for "boots on the ground" under the authorization Obama sought.
But skeptics including Republican Sen. Ron Johnson of Wisconsin appeared unconvinced, questioning whether contingency planning included a troop scenario if things were to spin out of control.
Kerry and Hagel emphasized repeatedly that the authorization sought by Obama was a limited strike and not a war declaration.
Sen. John McCain, who has pressed for tougher action on Syria, told CNN's "The Situation Room" that Kerry did a "good job" in getting the message out about the administration's intentions, but questioned whether he was effective enough overall in presenting a convincing case, especially to the public.
4) Obama has the power
A general consensus at the hearing was that Obama had the authority to act in Syria without congressional authority. Kerry asserted it several times, and senators from both parties thanked the administration for coming to Congress to hold the debate.
However, Kerry avoided a direct response when asked several times if Obama would act anyway in the event Congress rejected a military response.
He told one questioner the president had not told him what he would do, and Kerry repeatedly declared that such a rejection would harm the U.S. standing among its allies while emboldening its enemies.
One senator who rejected Obama's authority was Republican Rand Paul of Kentucky, a libertarian who calls for a reduced U.S. military role in the world.
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.