When Allied leaders and Jewish organizations received clear evidence of Nazi genocide in 1941-1942, they largely failed to act - a devastating silence that may have cost countless lives. Walter Laqueur's "The Terrible Secret" investigates this systematic suppression of Holocaust information during World War II, tracing how knowledge of mass extermination reached various authorities following Germany's invasion of Russia. Through analysis of cables, eyewitness accounts, and official correspondence, the research documents that President Roosevelt, intelligence officials, and Jewish leadership possessed credible evidence of Nazi atrocities months or years before mounting any substantial response. Multiple factors contributed to this deadly information vacuum: Nazi linguistic deception masking their true actions, Allied reluctance to divert military resources, fears of antisemitic backlash, and widespread disbelief about the sheer scale of the killing. Earlier disclosure could have increased escape attempts, deterred cooperation from Nazi satellite states, and potentially spurred Allied intervention. The findings underscore why Holocaust remembrance remains vital for genocide prevention and highlight the Jewish community's evolving approach to advocacy and self-determination in response to institutional failure.