On April 1, 1948, David Ben-Gurion wrote in his journal about “the development of science and speeding up its application in warfare.” A month and a half later, he wrote about “biological materials” that were purchased for $2,000. Only now, 74 years later, has a connection between these two entries come to light. The disturbing story behind them was recently uncovered by historian Benny Morris and historian and Israel Prize laureate Benjamin Z. Kedar following extensive archival research. Evidently, the excerpts from the diary of the man who would become Israel’s first prime minister are traces of his involvement in a secret operation to poison the drinking water of Arab communities during the War of Independence.