(RNS) Research for my upcoming biography of Rabbi Stephen Wise, who was a pillar of the Zionist movement and perhaps the most influential U.S. rabbi during World War II, has led me to several historical archives where I've spent hours opening large boxes of memos, telegrams, documents, photos, letters, and microfilms.

It's frequently a tedious boring task — but not during my recent visit to the Franklin D. Roosevelt Presidential Library in Hyde Park, N.Y.

There were few tourists, no metal detectors and X-ray machines, no long lines of people waiting to view the simple grave of Franklin and Eleanor Roosevelt. But when I read and touched the archival material, an extraordinary emotion overcame me.

Despite the gorgeous summer weather and the tranquil surroundings of the Roosevelt estate, I was transported back to the turbulence of the 1930s and 1940s: the Great Depression, Nazism, World War II, and the Holocaust. My research centered on the problematic relationship between the rabbi and the president. Even though Wise met with FDR 13 times in the White House, there are no photos of any of those encounters.

I also gained insights into other leaders of that era. There was Chaim Weizmann’s personally signed letter — written in London in 1943 on tissue paper — addressed to Undersecretary of State Sumner Welles. Weizmann, who five years later would become Israel’s first president, provided the American diplomat with a detailed analysis of the Zionist enterprise during the war.

Other documents focused on the Allies' options for destroying the Auschwitz death camp. Tragically, it never happened. Reading formerly “Secret” or “Confidential” documents was a sobering experience because unlike FDR, Wise, Welles, Weizmann and other leaders of the time, I knew, for better or worse, how it all turned out in the end.

Although much of the material was composed in a formal, even stilted English, the intense emotions of the time came alive: A monstrous global war was taking place, 12 million American men and women were in uniform, and in 1942, victory over the Axis powers was in doubt. The archives reveal the enormous hatred directed at FDR, a Hudson Valley patrician, from many Americans who considered him a “traitor” to his highborn socioeconomic class. 

Wise and other Jewish leaders had three major goals: breaking America’s cruel quota system that prevented many Jewish refugees from entering the U.S.; saving Jews in Nazi-occupied lands; and establishing a “Jewish Commonwealth,” today’s State of Israel.

It was painful to read the urgent appeals sent to a White House that was publicly friendly to Jewish concerns but often internally ambivalent. The State Department featured some anti-Semites in leadership positions. The War Refugee Board, created in 1944 at the insistence of Treasury Secretary Henry Morgenthau Jr., saved thousands of Jews late in the war, but director John Pehle was often blocked in his efforts to rescue more because of inaction, procrastination and hostility from key government authorities.

One document will always haunt me. “Psychological Warfare: Instructions for Jews in Nazi-occupied Territory” was prepared for distribution in various languages throughout Europe. Seventy years later, it remains gruesome reading:

“Those Jews who have been able to survive … should take measures which will prevent them from being victims … We know how difficult it is to make this work a reality … do not wear the yellow badge … do not register as Jews … go into hiding with guerilla forces … disguise yourselves … do nothing which would direct the attention of Nazi authorities to your existence … Pretend to be a Gentile or one of the foreign workers of whom there are millions in Nazi-occupied territories …

“If you are in a critical situation … try bribing a Nazi official … Take full precautions before you speak freely to … the Underground … Be in contact with only two other persons, and that each of these persons should not know that you are working with the other … save those who are least expendable, and also those who are in the greatest danger.”

After reading these frightening words, I had to rush outside into warm sunshine, gulp some fresh air and reassure myself it was really 2012, not 1943. Even so, I was shivering and crying. This time, it was good to come back to the future.

Rabbi Rudin, the American Jewish Committee's senior interreligious adviser, is the author of the recently published “Cushing, Spellman, O'Connor: The Surprising Story of How Three American Cardinals Transformed Catholic-Jewish Relations.”

(Rabbi Rudin, the American Jewish Committee's senior interreligious adviser, is the author of the recently published “Cushing, Spellman, O'Connor: The Surprising Story of How Three American Cardinals Transformed Catholic-Jewish Relations.”)