The surprise Japanese attack on Pearl Harbor in 1941 left behind not only a devastated US Pacific Fleet reeling from the shock but also a shocked nation. Americans were also white-hot with rage and had a burning desire for vengeance. The man who had overseen that attack – and a series of Japanese naval victories in the following months – was Admiral Isoroku Yamamoto. Commander of the Combined Japanese Imperial Fleet, Yamamoto, was Osama bin Laden of World War II. Unlike the Al Qaeda leader, however, the Japanese admiral actually liked the US.
Yamamoto had studied at Harvard University, served two stints as a Japanese naval attache in Washington, DC, spoke fluent English, and was quite fond of America. He advised against going to war with the US and only led his countrymen against America because it was his duty as a Japanese officer, though he did so reluctantly. Of course, such caveats were irrelevant to Americans back then. Even if they had known about them, they would have still hated and wanted to get Yamamato as much as their descendants hated and wanted to get bin Laden. They finally did so in one of WWII’s most fascinating missions.
Overwhelming Reason for Merciless Capture
Yamamoto, a prophet of the naval airpower that devastated Pearl Harbor, was the Japanese Navy’s dominant figure. A determined and aggressive commander, he drew bold and imaginative plans. He also possessed the kind of strong leadership that ensured such plans were embraced by his subordinates, who idolized Yamamoto and strove to execute his orders with vigor and skill. A chess champion of the Japanese Navy, he also became an excellent poker player while studying and serving in America. US intelligence judged him “exceptionally able, forceful and quick thinking.”
In short, American commanders realized that Yamamoto was one of a kind. Getting him was about more than mere payback. He was preeminent in all categories, and if anything happened to him, any potential Japanese successor was bound to be personally and professionally inferior. Not to mention that Yamamoto’s death would both demoralize the Japanese and simultaneously give Americans a huge morale boost. A hiccup, though, was that getting Yamamoto lay more in the realm of wishful thinking and revenge fantasies rather than in the world of the possible and probable.
That changed with a fortunate break on April 14th, 1943. US Navy intelligence intercepted a coded telegram sent in Japanese Naval Cipher JN-25D. Unbeknownst to the Japanese, the JN-25 code had been cracked by a secret US cryptanalysis effort known as “Magic.” American cryptographers, whose ranks included future United States Supreme Court Justice John Paul Stevens, deciphered the telegram to reveal a momentous message. It began: "On April 18 CINC Combined Fleet will visit RXZ, R__, and RXP in accordance with the following schedule..." CINC Combined Fleet was the hated Admiral Isoroku Yamamoto.
The decrypted transmission stated that Yamamoto and accompanying staff would fly on an inspection and morale-boosting mission from Rabaul to the northern Solomon Islands. His itinerary included visits to Balalae, the Shortland Islands, and Buin. The message provided detailed departure and arrival information, mode of travel, the number of escort fighters, and contingencies for bad weather. The party would leave Rabaul in two Mitsubishi G4M “Betty” medium bombers. The one carrying Yamamoto would be escorted by six Mitsubishi A6M “Zero” fighters, while the other, carrying his chief of staff, Vice Admiral Matome Ugaki, was assigned an escort of three Zeros. Takeoff was scheduled for 6 AM, Tokyo time, for an 8 AM arrival at Balalae Airfield, near Bougainville.
That would be the closest Yamamoto had ever come to American front lines and a golden opportunity not to be missed. The information quickly worked its way up the chain of command to Admiral Chester W. Nimitz, Commander in Chief, US Pacific Fleet and Pacific Ocean Areas, who forwarded it on to Washington. There, President Franklin Delano Roosevelt reportedly authorized Secretary of the Navy Frank Knox to "get Yamamoto." The following day, April 15th, Nimitz directed Admiral William F. Halsey, commander in the South Pacific, to begin preliminary planning. Halsey passed the project on to Rear Admiral Marc A. Mitscher, commander of aerial assets in the Solomons.
Shoot to Kill: Operation Vengeance
Planning began immediately to kill the enemy admiral blamed for Pearl Harbor and was given the apt codename Operation Vengeance. A plan to intercept and shoot down Yamamoto's plane had to be precisely timed. For American fighters to take off from a base hundreds of miles away and intercept an enemy party in the air hundreds of miles from its takeoff point, everything had to go in accordance with an exacting schedule. If all went right, US fighters taking off from Henderson Field in Guadalcanal at 5:25 AM Tokyo time could fly a circuitous route that would intercept Yamamoto at 7:35 AM near Bougainville.
A few minutes’ deviation from the schedule by either side could doom the mission and result in the Americans arriving at an empty patch of sky devoid of enemy airplanes. Fortunately for the Americans, and unfortunately for the Japanese, their target was known for his compulsive punctuality – a fact known to US intelligence from Yamamoto’s time in America. There was a hiccup, however: the flight route from Rabaul to Bougainville was beyond the range of US Navy airplanes. However, it was within the range of US Army Air Forces P-38 Lightning fighters that had been recently deployed to Guadalcanal.
With distinctive twin booms on either side of a central pod that contained the cockpit and weapons, the Lockheed P-38 was one of WWII’s most recognizable planes. It was also the only successful twin-engine fighter of the war, with over 10,000 produced during the conflict. The Lightning's prototype was the world's fastest aircraft when it was first introduced in 1939, and it remained one of the fastest climbers until the war's end. Operationally deployed in 1941, P-38s saw service in both the European and Pacific theaters but excelled more in the Pacific because their long-range capabilities were well suited to that theater’s vast distances.
The Lightning's machine guns were placed in the plane’s nose, an unusual configuration for American fighters of WWII, which typically used wing-mounted machine guns. While wing-mounted guns were calibrated to shoot at criss crossing trajectories of between 100 to 250 yards, the Lightning's straight-ahead arrangement gave it a significantly longer useful range. P-38s could reliably deliver effective and aimed concentrated machine-gun fire up to 1000 yards. America's top two WWII aces, Richard Bong and Thomas McGuire, both flew P-38s.
Accordingly, 18 P-38G Lightnings, each armed with four .50 caliber machine guns and one 20mm cannon and equipped with drop tanks for extra range, were selected for Operation Vengeance. They were to be led by USAAF Major John Mitchell, an ace pilot who commanded the 339th Fighter Squadron, 347th Fighter Group. A flight of four was designated as a “killer team” to go after the two bombers. The remaining Lightnings, whose numbers included two spares, were to fly air cover above and keep at bay the escorting Japanese Zeros and swarms of other enemy fighters expected to take off from nearby airfields.
Visiting Vengeance Upon Yamamoto
One worry about Operation Vengeance was that it might tip off the Japanese that their naval codes had been cracked. It was eventually decided that the secret could be kept, so long as measures were taken to keep the sources of the intelligence from unauthorized personnel and the press. The American pilots’ briefing told them that Australian intelligence assets had spotted a Japanese bigwig boarding an airplane at Rabaul. They were not told that their target was Yamamoto until just before takeoff – a calculated breach of security to give them extra incentive to exert all possible effort into ensuring the mission’s success.
It was vital to avoid Japanese detection at all costs. From Henderson Field to the interception point was 400 miles. However, there were plenty of Japanese spotters in islands along that route who might alert Yamamoto’s flight to turn around or divert to the nearest airfield. So a circuitous 600-mile route was chosen instead. It would first take the P-38s southwest from Henderson Field, followed by a hook that swung wide of the islands between Guadalcanal and Bougainville and the enemy watchers therein. The flight would have to change course multiple times in radio silence while paying attention to exact times, speeds, compass settings, and altitudes. Deviation by a few degrees or a few minutes, and the crucial interception would be missed.
It worked like clockwork. Skimming the ocean at 30 feet to avoid detection, Major Mitchell and sixteen P-38s – mechanical failures had forced two to abort – reached the interception point at 7:34 AM Tokyo time, within one minute of Yamamoto. The Japanese admiral and the American flyers were right on schedule. As the enemy flight was descending for its 8 AM scheduled landing, Mitchell and his pilots dropped their auxiliary tanks, turned right in parallel with their targets, and began a full-power climb to meet them. The drop tank of one killer team pilot, Lieutenant Besby F. Holmes, failed to drop, so he and his wingman turned back to sea. That left two killers, Captain Thomas G. Lanphier Jr. and Lieutenant Rex T. Barber.
As their escorting Zeros dove down to intercept the P-38s, the two transport bombers dove to ground level to flee the sudden attack. Lanphier turned to meet the Zeros head-on while Barber made a steep banking turn towards the targets. He momentarily lost sight of them, but when he came out of the turn, he found himself directly behind a Betty and immediately opened fire. The bomber emitted heavy smoke after it was hit in both its engines, rear fuselage, and tail section, and Barber narrowly avoided a collision when it suddenly rolled to the left. When he looked behind, he saw a column of smoke rising from the ground.
Barber had just killed Yamamoto, whose transport bomber crashed into the jungle with no survivors. Not knowing which bomber carried Yamamoto, Barber continued on in search of the other one. He found it low above the water, trying to evade Lieutenant Holmes, who had returned to the fight after his drop tank finally detached. The bomber was already crippled and trailing white vapor when Barber finished it off with a burst that shredded metal debris off of it. Its chief passenger, Yamamoto’s chief of staff, Admiral Ugaki, was injured but survived along with two others.
The P-38s then broke off contact. Since avoiding detection did not matter anymore, they flew a 400-mile straight line flight back to Guadalcanal, which they reached after completing a 1000-miles-long mission. Yamamoto's crashed bomber was located by the Japanese the following day, and his corpse was recovered from the wreckage strewn around the crash site. To keep their code-breaking a secret, US authorities did not let on that they knew who was in the downed bombers. The American public only learned that the hated enemy admiral was killed on May 21st, 1943, when the Japanese finally announced that Yamamoto had: “engaged in combat with the enemy, and met gallant death in a warplane.”
Air Force Magazine, March 1st, 2006 – “Magic and Lightning”
Air Power History, Vol. 50, No. 2, Summer 2003 – “The Yamamoto Mission”
Burke, Davis – Get Yamamoto (1969)
Hampton, Dan – Operation Vengeance: The Astonishing Aerial Ambush That Changed World War II (2020)
History Net – Death by P-38: When America Killed Japan’s Top Admiral
Japan Times, September 29th, 2008 – “Use of Outdated Code Led to Ambush that Killed Yamamoto, US Files Show”
Kahn, David – The Code Breakers: The Story of Secret Writing (1967)
Oregonian, The, April 18th, 2013 – “Historian Says Oregonian Rex Barber Shot Down Yamamoto in World War II”