Six months after the Japanese attack on Pearl Harbor, the June 7, 1942, edition of the Chicago Sunday Tribune trumpeted news of a stunning American victory over a Japanese armada at the Battle of Midway. “Jap Fleet Smashed by U.S.; 2 Carriers Sunk at Midway: 13 to 15 Nippon Ships Hit; Pacific Battle Rages,” the front-page headlines read. And in the center of the page, an intriguing side story: “Navy Had Word of Jap Plan to Strike at Sea.” It was a fascinating, and detailed, description of much of what American intelligence knew beforehand of the enemy’s fleet and plans. Indeed, it was too detailed. The report — 14 paragraphs long — suggested a secret U.S. intelligence coup, and it became one of the biggest and potentially damaging news leaks of World War II. The leak hinted that the United States had cracked a Japanese communications code, sparking fury in the Navy and the administration of President Franklin D. Roosevelt, and starting an “espionage” probe by the FBI. It also led to a sensitive grand jury investigation for which testimony would be sealed for more than seven decades. In December, Elliot Carlson, a naval historian in Silver Spring, Md., along with the Reporters Committee for Freedom of the Press, the Naval Institute Press and the Organization of American Historians, among others, won a court fight to unseal the old testimony in the case, which is kept in the National Archives. “This is the only time in American history that the United States government has … taken steps toward prosecuting a member of the media under the Espionage Act,” Katie Townsend, the Reporters Committee litigation director, said in an interview. This week, with leaks again making big news, the United States marks the 75th anniversary of Midway, the epic 1942 battle that raged from June 4 to June 7 and turned the tide of war in the Pacific theater. The American assault on the Japanese fleet was “the single most decisive aerial attack in naval history,” according to historians Jonathan B. Parshall and Anthony P. Tully Battle of Midway footage from 1942 documentary 1:15 The United Staves Navy released a documentary that contains footage from the Battle of Midway in June 1942. (Video: U.S. Navy) The Japanese navy was crippled by the loss of four aircraft carriers — all of which had been used in the attack on Pearl Harbor — and hundreds of planes and sailors when it was ambushed by a smaller U.S. force that had been forewarned by good intelligence. American code breakers had figured out where and when the enemy planned to strike, and the military acted accordingly. But it was critical that the Japanese not learn of the breach, lest they change their codes and confound their U.S. foes. Yet, here, the day the battle ended, was an American newspaper suggesting such a breach to the world. Chicago Sunday Tribune front page. (Chicago Tribune) “The strength of the Japanese forces with which the American Navy is battling … was well known in American naval circles several days before the battle began,” the Tribune report began. “The advance information enabled the American Navy to make full use of air attacks on the approaching Japanese ships.” The story went on to describe the three parts of the planned Japanese attack: a striking force, a support force and an occupation force. It detailed how many ships were involved, and named the ships and their types. “It was a huge scandal,” Carlson, who is working on a book about the case, said in a telephone interview Thursday. “It enraged the Navy high command. It enraged the Roosevelt administration.” The story did not explicitly say a code had been broken, Carlson said. But “any knowledgeable reader of that story would have known that [it] had to come from American cryptanalysis of the Japanese naval code,” he said. “The Navy … thought any reasonably intelligent person reading that story would say, ‘Hey, the American Navy has broken the Imperial Navy’s operational code.’ ” The secret deal the Associated Press made with the Nazis during WWII The Navy’s information on Japanese plans had been gleaned from weeks of scrutiny of enemy message traffic being conducted in the compromised code. U.S. intelligence officials were able to predict what direction the attack would come from and what time of day it would start, and experts were off by only 24 hours in forecasting the date the attack would begin, according to historian John Costello’s study of the Pacific war. At first, the United States was unsure where the enemy planned to attack. Japanese communications kept referring to a location code-named “AF.” The Navy guessed it was Midway, but it had to be sure. To find out, Navy Capt. Joseph J. Rochefort, a code breaker, suggested a ruse. Midway was instructed to issue an emergency call in plain English saying that its water distillation plant had broken down. The report was duly picked up by enemy eavesdroppers, who radioed superiors that “AF” was running short of water, according to Costello. When the Japanese fleet approached Midway, the Americans were lying in wait. The Japanese force was virtually wiped out. But the U.S. fleet was hurt, too. The aircraft carrier USS Yorktown was sunk, and an entire squadron of 15 torpedo planes was shot down. Only one man, Ens. George Gay, survived the doomed attack of Torpedo Squadron 8. Several American pilots downed in the battle were picked up by the Japanese navy. They were interrogated and executed, and their bodies were thrown into the ocean, according to historians Parshall and Tully. The Tribune story ran in other papers, including the old Washington Times-Herald and the New York Daily News. It carried no byline and bore a Washington dateline, but it was the product of a Tribune war correspondent in the Pacific named Stanley Johnston. An Australian who had once mined for gold in New Guinea, Johnston had been aboard the aircraft carrier USS Lexington when it was sunk during the Battle of the Coral Sea in early May 1942, Carlson said. Johnston was a World War I veteran with a trim mustache and had fought at Gallipoli as a teenager. He had started as a war correspondent for the Tribune in Britain in 1940, according to a 1942 Tribune profile. Known as “Johnny,” he had almost been killed when German planes bombed the Dover hotel where he and other reporters were staying. When the United States entered the war, the Tribune sent Johnston to the Pacific, where he asked to be assigned to the Lexington because there were no other reporters on board, the newspaper said later. “He’s been a recurring puzzle and mystery all these years for the Navy,” Carlson said. In the Coral Sea, the Lexington was crippled by enemy dive bombers and torpedo planes, and it suffered post-attack explosions so serious that it had to be abandoned. But most of the nearly 3,000-man crew was rescued, including Johnston. The carrier was then sunk by an American destroyer. Johnston and other Lexington survivors were eventually put aboard the Navy transport USS Barnett and started for San Diego. While they were en route, Adm. Chester W. Nimitz, armed with the latest intelligence, “circulated a message to all of his commanders at sea giving them a little preview … about the battle of Midway that was going to occur in four or five days,” Carlson said. Among other things, the crucial message — No. 311221 — laid out in detail the makeup of the enemy force. “That particular dispatch showed up on the Barnett,” Carlson said. “It was not intended to go there, but it turned out the transport ship had the equipment to decode whatever it wanted to.” The dispatch wound up in the hands of the Lexington’s rescued executive officer, Cmdr. Morton T. Seligman, who happened to be bunking with Johnston. “So you put him in the same room with the dispatch, and the Navy and everybody else put two and two together. Much of the content of Nimitz’s dispatch appeared in Johnston’s story.” Johnston later testified that he had gleaned the crucial information from a “scrap of paper” with doodling on it, which he found on a table in the ship’s crowded quarters, and which he then threw away. Johnston landed in San Diego on June 2, and was in Chicago on June 4. When he heard about the unfolding battle, he told his editor he had some “dope” on the Japanese fleet, according to a 1942 report to the Navy and the Justice Department by former U.S. attorney general William D. Mitchell, who was handling the investigation. Johnston was told to write the story. “The description in the article of the Japanese Midway fleet is almost an exact duplication of the information contained in the Nimitz dispatch,” Mitchell wrote, and Johnston later admitted copying a document with “some statement on it about the Japanese fleet.” Johnston almost certainly saw and copied the dispatch, Mitchell believed. But there was no proof that he knew the dispatch was secret. “The fact that it was left lying around would indicate its lack of ‘secrecy,’ ” Mitchell wrote. Plus, he feared a criminal prosecution could reveal further wartime secrets. The Roosevelt administration wanted to pursue it anyhow. In Chicago, in August 1942, federal prosecutors seated a grand jury, which heard testimony. In the end, no one was indicted. The testimony was sealed, and remained so until last December. The Justice Department had argued against unsealing it, saying that such testimony should always remain sealed to protect witnesses and the innocent. But after more than seven decades, the courts ruled in favor of the historian. Carlson said Johnston’s story did not help the Japanese. “They never heard of the article,” he said. The Japanese did soon change their code, but not because of the leak. “They changed it because it was due to be changed,” he said. Twenty years later, on Sept. 13, 1962, when Johnston died of an apparent heart attack at age 62, the Chicago Tribune ran his obituary on the front page. Magda Jean-Louis contributed to this report. Read more Retropolis: By Michael Ruane Michael E. Ruane is a general assignment reporter who also covers Washington institutions and historical topics. He has been a general assignment reporter at the Philadelphia Bulletin, an urban affairs and state feature writer at the Philadelphia Inquirer, and a Pentagon correspondent at Knight Ridder newspapers. Sumner Redstone, my source for this, suggests graymail saved this case going to trial. Very Assange.