Congress is not officially back in session until next week, but U.S. senators returned to D.C. on Tuesday for their first public hearing on possible action against Syria.
Three top Obama officials answered questions for hours, hoping to build bipartisan support for military action against Syria.
Sen. Barbara Boxer, D-Calif., said that if America doesn't retaliate against Syrian President Bashar al-Assad for using chemical weapons against his own people, Iran will view the United States as a paper tiger.
"I believe we cannot close our eyes to this clear violation of long standing international laws. I believe America's morality, America's reputation and credibility are on the line," Boxer said.
Other senators, including Sen. Jim Risch, R-Idaho, don't agree that the U.S. should take action against Syria.
"I am reluctant because part of where this stems to, where this is going to go, as to the limit we are going to put on it," Risch said. Secretary of State John Kerry pushed for consensus, saying the decision to endorse military action is one of the most important for the Senate Foreign Relations Committee.
"When someone kills hundreds of children with a weapon the world has banned, we all are responsible," Kerry said.
Congress will vote next week to authorize -- or not -- military action against Syria. Tuesday's public hearing is being followed up by a closed-door hearing on classified information Wednesday.