Sen. Tom Udall (D-NM) pushed back on John Kerry more than most Democrats at Tuesday's hearing, and though he never explicitly asked it, the implied question was, "What are the chances doing something will be worse than doing nothing?" After some back-and-forth, Kerry compared U.S. inaction now to an incident in the days leading up to World War II:

It's not a question of what will happen if we don't do it; it's a certainty. Are you going to be comfortable if Assad, as a result of the United States not doing anything, then gasses his people yet again, and the world says, "Why didn't the United States act?" History is full of opportunity of moments where someone didn't stand up and act when it made a difference. And whether you go back to World War II or you look at a ship that was turned away from the coast of Florida and everybody on it lost their lives subsequently to German gas, those are the things that make a difference. And that's what's at stake here.

The incident Kerry referred to is the voyage of the St. Louis. In 1939, the St. Louis, a transatlantic liner, carried hundreds of Jewish refugees trying to escape the Third Reich from Germany to Cuba. The 938 passengers were turned away in Havana, then Miami, and after the ship ultimately returned to Europe, 254 of its passengers died in the Holocaust—so not "everybody," as Kerry said.

http://www.slate.com/blogs/weigel/2013/09/03/john_kerry_compares_sy...