Congress is reviewing the Iran nuclear deal and the battle lines are already clear with Republicans solidly united against it and Democrats divided. The president has said he will veto any congressional action disapproving the agreement, meaning that a handful of Democrats will have to vote to override the veto if this unverifiable and dangerous deal is to be rejected. Democrats have to choose between the national interest and partisan politics, between morality and loyalty to the president, and between endangering the lives of millions and acting to protect them from a potential nuclear holocaust. In 1939, Congress faced an even more stark opportunity to save lives and, following the lead of a popular Democratic president, made a fatal decision.

In February 1939, Senator Robert F. Wagner, Sr. (D-NY) and Representative Edith Rogers (R-MA) introduced legislation to bring 20,000 German Jewish refugee children, ages 14 and under, to the United States. This was exactly three months after Kristallnacht, the “Night of Broken Glass” in Germany, when synagogues were burned to the ground, Jewish shops looted, Jewish citizens attacked and thousands of men arrested and imprisoned in Dachau. The whole world saw the danger facing the Jews in Germany and did nothing to confront Hitler. The urgency of acting should have been apparent to all, however, after Hitler declared on January 21, 1939: “We are going to destroy the Jews.”

The “Final Solution” had not yet begun; Jews were actually encouraged to leave Germany, but most nations shut their doors. During the debate in Congress on Wagner-Rogers, for example, the St. Louis was prevented from docking in the United States. The ship was forced to return to Europe with more than 900 Jewish refugees aboard; hundreds would eventually be killed.

Meanwhile, British authorities agreed to allow children under the age of 17 to enter Great Britain from Germany and German-annexed territories (i.e., Austria and the Czech lands) beginning on December 2, 1938. Approximately 10,000 children were ultimately saved by the British between 1938 and 1940 in the Kindertransport.

This was the context in which Congress considered admitting a group of Jewish children.

Roosevelt, who had allowed a small number of Jewish refugees into the United States on an emergency basis, would not support the bill (though Eleanor did privately). Public opinion opposed the legislation and critics argued that it was unconscionable to take children without their parents, and that the U.S. would soon be asked to admit 40,000 parents. Some claimed orphanages would be overburdened, that unemployment would be exacerbated, and that America should help its own children. Anti-Semitism, which was rife at the time, also contributed to the opposition to the rescue plan, which may explain why, a year later, Roosevelt and Congress quickly approved legislation to shelter in the United States thousands of British children endangered by German bombing raids.

The final discussion of the House and Senate bills to rescue the Jewish children was held on June 1. Without the president’s support, they died in committee.

What does this have to do with the Iran debate?

Iran is likely to acquire a nuclear weapon sooner or later under the unverifiable loophole-filled agreement. A nuclear Iran poses a threat to the Middle East and the West, but Iran’s leaders have only singled out one country as a target for destruction — Israel. Some may argue that there is a big difference between 1939 and today since there are no Jews in immediate need of rescue; however, the Jewish State is endangered by Iranian leaders whose threats echo those of Hitler. Do we take action now to ensure those threats cannot be fulfilled or risk the lives of millions in the hope the president’s rosy scenario plays out?

Obama has convinced himself that he knows more about Israel’s security than the leaders of Israel’s major parties, and dismisses their concerns by using the straw man argument that the only alternative to his irresponsible deal is war. Democrats in Congress may want to take Israel’s fears more seriously. Politically, they may face the wrath of a lame duck president, but they may also risk their own political futures by defying the will of the American public and their pro-Israel constituents. Morally, they may have to live with the knowledge that, like 1939, they could have acted, but did not, and condemned Jews and others in the region to death.

This may be the most significant issue facing the Jewish people in most of our lifetimes and politicians should not count on Jews’ broad commitment to the Democratic Party to save them if they choose partisan politics over saving lives. Hillary Clinton should also think very carefully before tying her future to an unenforceable agreement that could unravel on her watch. Democrats would also be wise to recall the fate of Jimmy Carter, whose anti-Israel policies produced the greatest defection of Jewish voters from the Democratic Party in history and contributed to his reelection defeat.

For many Jews, a vote in favor of this dangerous agreement will be unforgiveable.