The last picture of Adm. Yamamoto alive. It was taken shortly before his plane was shot down over Bougainville, April 18, 1943. National Archives photo

On April 14, 1943, naval intelligence scored another code-breaking coup. The message began: “On April 18 CINC Combined Fleet will visit RXZ, R–, and RXP in accordance with the following schedule . . .” Adm. Isokoru Yamamoto was planning an inspection visit of Japanese bases in the upper Solomon Islands. The information immediately went from Commander in Chief Pacific Fleet Adm. Chester W. Nimitz to Secretary of the Navy Frank Knox who delivered the news to President Franklin Roosevelt. Reportedly, the president’s response was, “Get Yamamoto.” Regardless of whether or not the president actually said those words, the order was given: kill the mastermind of the Pearl Harbor raid.

Squadron 339 P-38 must at all costs reach and destroy. President attaches extreme importance to mission. —Secretary of the Navy Frank Knox Top Secret Message April 17, 1943, to Adm. Chester W. Nimitz

Ironically, the target of American vengeance had repeatedly risked his life speaking out against war with the United States. As a result of postings in America and England, he saw how weak industrial Japan was compared to the United States and Great Britain.

When asked by Prime Minister Prince Fumimaro Konoye how war between Japan and America would go, Yamamoto replied he would “run wild for six months or a year, but after that I have utterly no confidence.”

On Sept. 18, 1941, in a meeting with classmates from his hometown of Nagaoka, Yamamoto said, “It is a mistake to regard Americans as luxury loving and weak. … Remember that American industry is much more developed than ours, and – unlike us – they have all the oil they want. Japan cannot vanquish the United States. Therefore we should not fight the United States.”

“That’s too bad, Watanabe. If I die before you, tell the Emperor that the navy did not plan it this way from the beginning.”

But when his government decided to go to war, Yamamoto set aside his personal feelings and vowed to do everything he could to achieve victory.

Yamamoto was playing chess with Capt. Yasuji Watanabe, a member of his staff, when they heard over the radio the news about the Pearl Harbor attack and Japan’s declaration of war being delivered afterward. He said, “That’s too bad, Watanabe. If I die before you, tell the Emperor that the navy did not plan it this way from the beginning.”

An astonishing string of Japanese victories followed. Then, almost six months to the day after Pearl Harbor, the Imperial Japanese Fleet was defeated at Midway. When the grueling Guadalcanal campaign ended in early 1943, Yamamoto saw the handwriting on the wall. In a letter to a friend in Marchs, he wrote, “I sense that my life must be completed in the next hundred days.” He headed south to oversee the next stage of operations.

Launched on April 1, 1943, Operation I-Go was a joint Japanese navy-army aerial counter-offensive to stop American advances in the Solomons and New Guinea. On April 13 Yamamoto, now headquartered in Rabaul, decided he needed to inspect Japanese bases in the upper Solomons. On April 16, after accepting without challenge exaggerated pilot claims of ship sinkings and aircraft shootdowns, Yamamoto suspended the offensive pending the completion of his inspection.

Eighteen P-38s (sixteen for the attack, two spares) were selected and equipped with special drop tanks. A “killer” flight of four fighters led by Capt. Thomas G. Lanphier, Jr. would attack the two Betty bombers containing Yamamoto and his staff while the others attacked the fighter escorts.

Nimitz’s window of opportunity to intercept Yamamoto had to be precisely timed. Fortunately for him, his adversary was noted for punctuality. Though Yamamoto’s route was beyond the range of naval fighters, it was within that of Army Air Force P-38Gs recently deployed to Guadalcanal.

On April 17, Squadron 339 commander Maj. John Mitchell USAAF found himself assisting Vice Adm. Marc Mitscher and other senior commanders in planning the attack. The intercept would occur over the island of Bougainville. A 1,000-mile round trip was plotted, with a roundabout approach route of 600 miles from the south. Eighteen P-38s (sixteen for the attack, two spares) were selected and equipped with special drop tanks. A “killer” flight of four fighters led by Capt. Thomas G. Lanphier, Jr. would attack the two Betty bombers containing Yamamoto and his staff while the others attacked the fighter escorts.

At 7:25 a.m. on April 18, the first anniversary of the Doolittle Raid, the P-38s of Operation Vengeance took off. At 9:34, they arrived at the intercept point, and, right on time, saw their target.

Lanphier and 1st Lt. Rex T. Barber of the killer flight peeled off to attack the Bettys and immediate escorts while the other planes attacked the other escorts. Both bombers were shot down, for the loss of one P-38 and its pilot, 1st Lt. Raymond K. Hine.

“That son of a bitch will not be dictating any peace terms in the White House.”

Shortly before noon, as the returning P-38s prepared to land at Henderson Field, Lanphier radioed, “That son of a bitch will not be dictating any peace terms in the White House.” Yamamoto was dead. Lanphier’s statement, which he broke radio silence to say, was a misinterpretation of Yamamoto’s words. What Yamamoto had meant was that a military victory against America through winning a single battle, or even many battles, would be impossible.

Every pilot participating in the attack received the Navy Cross. A controversy arose as to who actually shot down Yamamoto’s plane, with both Lanphier and Barber making their claims. Historians have since determined it was Barber.