Rabaul, located on the island of New Britain, was the Imperial Japanese army and navy’s main forward operating base in the Southwest Pacific, containing a large anchorage, four major airfields, and more than 110,000 troops. Its strategic location put it at the crossroads of a two-prong offensive strategy that called for Gen. Douglas MacArthur’s forces in the southwest Pacific Area (SWPA) to advance north from bases in Australia and New Guinea and Adm. Chester W. Nimitz’s Pacific Ocean Area (POA) forces to advance west through the central Pacific. Operation Cartwheel was the campaign designed to eliminate Rabaul. As Rabaul’s location was near the border between SWPA and POA, Cartwheel’s campaign would cross both borders. Before any campaign against Rabaul could be launched, the U.S. Army and U.S. Navy had to answer an explosive question: Who would exercise overall command?

“We respected this type of strategy for its brilliance because it gained the most while losing the least.”

– Col. Matsuichi Juio, senior intelligence officer, Eighth Area Army, Rabaul

In World War II, relations between the Army and Navy were formal at best. Army Maj. Telford Taylor discovered just how bad cooperation was when his first assignment in Army Intelligence was to literally spy on the Navy Department to discover what had happened in the Battle of Savo Island. Making matters worse, the Navy’s hatred of MacArthur, a former Army chief of staff, bordered on the pathological. With the Navy demanding Nimitz be supreme commander in the entire Pacific and the Army backing MacArthur, the result was the POA and SWPA compromise.

That meant overall command in Cartwheel would be bifurcated. Adm. William Halsey Jr., who had succeeded Vice Adm. Robert Ghormley as commander South Pacific Area, a subordinate command under Nimitz, ceded control of his ground troops once they crossed into SWPA’s (MacArthur’s) territory, but retained independent command of naval forces on both sides of the border. With Cartwheel containing 13 proposed amphibious assaults over several months, such a command structure risked failure. Fortunately, when they met, Halsey and MacArthur hit it off well. MacArthur later wrote in his autobiography Reminiscences: “[Halsey] was of the same aggressive type as John Paul Jones, David Farragut, and George Dewey. His one thought was to close with the enemy and fight him to the death.” For his part, Halsey recalled, “Five minutes after I reported, I felt as if we were lifelong friends.”

Cartwheel kicked off on the third week of June 1943, with assaults on the islands of Woodlark and Kiriwina (Operation Chronicle) and New Georgia (the first stage of Operation Toenails). Woodlark and Kiriwina, needed as airfield sites, were captured unopposed. The Japanese Army had about 10,500 troops on New Georgia, however, and fighting to seize that island took a little over a month.

Cartwheel was in full swing when American and British leaders met in Quebec for the Quadrant Conference. The combined chiefs of staff conducted a re-evaluation of resources for the various theaters within the context of the build-up for Operation Overlord. Given the strength of Japanese defenses at Rabaul and an insufficient number of troops, landing craft, and supplies available to attack it, the decision was made to bypass Rabaul and isolate it with a ring of island outposts, initiating a strategy that came to be called island hopping.

Even if one accepts MacArthur’s lexicon gymnastics, the facts undercut his claim. With its concentration of archipelagos, SWPA had an advantage of geography over POA, whose widely spaced atolls limited strategic options. In addition, the high casualty count in the Battle of New Georgia (about 1,100 killed and 4,000 wounded) undercuts MacArthur’s assertion when compared to POA battles at Tarawa (about 1,000 killed and 2,100 wounded) and Kwajalein (about 400 killed and 1,500 wounded). Finally, MacArthur wanted to attack Rabaul. It was Army Chief of Staff George C. Marshall and the Joint Chiefs who said no.

Ironically, this strategy was credited to MacArthur, who was against it. In Reminiscences, he recalled his objections in a meeting with his staff in which he explained the difference between his by-pass strategy and island hopping: “I intended to envelop [enemy strongpoints], incapacitate them, apply the ‘hit ’em where they ain’t – let ’em die on the vine’ philosophy. I explained that this was the very opposite of what was termed ‘island hopping,’ which is the gradual pushing back of the enemy by direct frontal pressure, with the consequent heavy casualties which would certainly be involved.”

Any account in Reminiscences has to be taken with a grain of salt (for instance in it MacArthur referred to Eleanor Roosevelt, whom he couldn’t stand, as an “old friend”). Even if one accepts MacArthur’s lexicon gymnastics, the facts undercut his claim. With its concentration of archipelagos, SWPA had an advantage of geography over POA, whose widely spaced atolls limited strategic options. In addition, the high casualty count in the Battle of New Georgia (about 1,100 killed and 4,000 wounded) undercuts MacArthur’s assertion when compared to POA battles at Tarawa (about 1,000 killed and 2,100 wounded) and Kwajalein (about 400 killed and 1,500 wounded). Finally, MacArthur wanted to attack Rabaul. It was Army Chief of Staff George C. Marshall and the Joint Chiefs who said no.

By the end of 1943, Rabaul was an impotent outpost. When Japan surrendered in August 1945, its roughly 69,000 surviving Japanese soldiers laid down their arms.