Secretary of State John Kerry told House Democrats during a Monday conference call that they face a "Munich moment" as they weigh whether to approve striking Syria to punish Syrian President Bashar Assad for using chemical weapons, two sources with knowledge of the call told NBC News.
The phrase is a reference to the 1938 Munich Pact that ceded control of part of Czechoslovakia to Nazi Germany -- a moment that history has harshly judged as an appeasement of Adolf Hitler that preceded World War II.
Kerry -- joined by other top officials, including National Security Adviser Susan Rice and Defense Secretary Chuck Hagel -- made the case for intervention to 127 House Democrats, many of whom expressed skepticism about a possible strike.
On the 70-minute call, some Democrats did come to the administration's defense, sources said. Minority Leader Nancy Pelosi was one; she told the call that preventing the spread of weapons of mass destruction as a critical piece of U.S. national security policy.
But others challenged administration officials. One member, Rep. Rick Nolan, D-Minn., compared Syria to the Vietnam War -- a conflict that started with an authorization of force in response to attacks on U.S. ships in the Gulf of Tonkin and eventually resulted in a war that killed tens of thousands of Americans.
Obama officials were in the grip of "historic amnesia," Nolan charged. The call is part of a sustained push by the administration to convince Congress to support using force after the president abruptly reversed course and decided not to strike Syria without first attempting to get congressional approval.
Obama faces a difficult path in the House, where many in his own party are already voicing skepticism about using force.
Some members who are typical allies of the president -- including Rep. Chris Van Hollen, D-Md., and Xavier Becerra, D-Calif., both members of the leadership -- have expressed concerns that the administration's proposal is too broad.
Kerry will have another opportunity to make his case to the lower chamber on Wednesday, when he testifies at a House Foreign Affairs Committee hearing.