With the United States caught up in an undeclared shooting war with Germany in late 1941 and President Franklin D. Roosevelt battling isolationists to deliver more support to the British and the Soviets in their desperate fight against Hitler’s forces, the release of top secret American war planning documents shook the nation. Seventy-five years later, the leak continues to stir up controversy. Some even claim that FDR himself was behind the leak of his own military’s blueprint for war against Nazi Germany.

World War II was raging in Europe and Indochina throughout 1941, sweeping up virtually every nation on earth—except the United States. Thanks in large measure to Americans’ isolationist leanings, the U.S. remained officially neutral while Hitler’s forces occupied almost all of Europe, part of North Africa and the Middle East, and advanced deep into the Soviet Union. Meanwhile Japanese forces were waging a long and brutal war in Indochina and preparing for a possible attack on the United States itself. President Franklin D. Roosevelt feared that a Nazi victory over the British and Red armies, the last remaining European holdouts against Hitler, would leave America truly isolated in the face of Germany’s and Japan’s murderous aggression. But in the heat of the tough 1940 presidential campaign, FDR had repeatedly assured American mothers, “Your boys are not going to be sent into any foreign wars.”

Then, on Dec. 4, 1941, came the explosive revelation that seemed to show he was lying. The U.S. military had prepared a lengthy report, called the Victory Program, which spelled out in detail war plans for defeating Germany, down to the sites for invasion and the number of ships, aircraft, tanks, and trucks needed. The deeply isolationist and anti-Roosevelt Chicago Tribune, which revealed the document’s existence, ran a huge block type headline declaring: “F.D.R.’S WAR PLANS!” (The same article appeared simultaneously in the Washington Times-Herald, a politically similar newspaper published by the cousin of Tribune publisher Colonel Robert McCormick.) The Tribune’s Capitol Hill correspondent, Chesly Manly, described “a blueprint for total war on a scale unprecedented in at least two oceans and three continents, Europe, Africa, and Asia.” The Victory Program called for a draft army of 5,000,000 troops, from a total manpower of more than 10,000,000 men in uniform, as part of a general national war mobilization. The U.S. would, Manly wrote, invade Europe on the specified date of July 1, 1943, in “the final supreme effort… to defeat the mighty German army…”