World War II was at its height; American forces were fighting on two fronts, and the government cast its intelligence nets as widely as they could for any bit of information on the moves and intentions of the country’s enemies — and even its friends. A vast information gathering operation — part clandestine and part open — was set up, and within it, in a forgotten corner of a small agency, a handful of American intelligence gatherers were tasked by the nation with spying on America’s Jews.

What they found varied wildly in its significance: real-time reports of the Nazis’ mass persecution of European Jewish populations that would later be understood cumulatively as the Holocaust; accounts of meetings between leaders of Vladimir Jabotinsky’s Revisionist Zionism movement and Republican Party leaders about their shared distrust of the Roosevelt administration’s close wartime ally Great Britain; multiple Jewish informants denouncing World Jewish Congress founder Nahum Goldmann as a scoundrel; a future leader of the Mossad, Israel’s foreign intelligence agency, conveying information about American Jewish diplomatic activities in the lead-up to the founding of the United Nations, and even a plan bruited by Zionist leaders to finance the establishment of Arab settlements in Iraq to which Arabs living in Mandatory Palestine and Transjordan could be removed.

These and other nuggets are in secret U.S. government documents, declassified in the 1980s and being analyzed only now for the first time. Collectively, they disclose a widespread domestic spying operation during WWII that targeted Jews, Jewish organizations and Zionist activity.

Since their routine declassification, these documents have sat, unexamined by anyone. But the Forward’s review of them shows that no piece of information was too small and no Jewish leader too obscure for the “Palestinian Desk” operated by the Foreign Nationalities Branch of the CIA’s precursor agency, known as the Office of Strategic Services.

Perhaps most surprising, the spy agency’s primary source for much of this intelligence was other Jews, some of them highly placed officials in Jewish agencies who, in a wartime context, saw providing such information as an act of patriotism.