When lawmakers return to Washington after Tuesday's congressional elections they will resume a debate they began with some reluctance last month on the U.S.-led fight against Islamic State militants in Syria and Iraq.
With the U.S.-led coalition increasing air strikes but no signs the militants have been weakened, Congress appears ready for a broader discussion on the operations than it was prepared to hold during the run-up to the election.
The temporary authorization for President Barack Obama's plan to arm and train moderate Syrian rebels - one element of the campaign - expires on Dec. 11, so lawmakers will have to take up that issue when they return from recess on Nov. 12.
A handful of lawmakers are also pushing for Congress to consider a broader Authorization for the Use of Military Force (AUMF), which would set out guidelines for the overall effort to halt the militants.
"We should not be asking servicemembers to go into harm's way without ensuring there is a political consensus in support of the mission," said Democratic Senator Tim Kaine, a leading advocate for an AUMF vote.
Sometime in the busy session between the elections and the start of a new Congress in January, Obama will also have to ask Congress to approve more funds to pay for an extended campaign.
Congress approved a narrowly focused plan to arm and train Syrian rebels in September, but that show of unity appeared unlikely to be repeated in a Congress deeply divided along partisan lines.
When it comes to a broader authorization, the two parties cannot agree on when a vote should take place, let alone on the content. Republicans say a vote should be delayed until the new Congress begins in January, by which time the Senate may have a Republican majority.
POLITICAL RISKS OF A DEBATE
Any debate on the issue, which will force members to take a public stand, is politically risky.
Although Americans worry about the threat of the Islamic State militants, who have taken over parts of Syria and Iraq and beheaded two American journalists since August, they are deeply wary of another entanglement in the Middle East.
With an eye on presidential elections in 2016, Democrats are reluctant to upset their anti-war base. Obama won the White House in 2008 partly because of his opposition to the Iraq War.
Republicans do not wish to be seen supporting Obama's strategy, which could be risky if the campaign goes badly, and may not want to alienate the party's growing isolationist wing.
Some Republicans said they want to give Obama more tools than air strikes to destroy the militant group, including combat troops. But anti-war Democrats favor explicitly barring the use of American ground troops.