This was the Allied overall designation for the plans created by General Douglas MacArthur’s South-West Pacific Area command for its operations to capture key points along the north coast of New Guinea’s western end, and thus to provide the jumping-off points for further operations to the north and also to isolate Japanese garrisons which would then be unable to play any further part in the war (1943/44).
As defined during the last stages 1943, MacArthur’s South-West Pacific Area command embraced everything to the south of the equator between 159° and 133° E. From this point the demarcation line swept to 20° N, west to the coast of China, south-west along the coast of Indo-China and Malaya, round the east coast of Sumatra, then east to 110° E and south to an indefinite point. Thus the SWPA included most of the Solomon islands group, all of Australia, New Guinea, the Bismarck islands group, the Philippine islands group, and much of the Netherlands East Indies. The SWPA’s boundary had initially been set at 160° E, but had then been moved farther to the west in order to bring all of Guadalcanal within the area of responsibility of Admiral William F. Halsey’s South Pacific Area command.
For operations in the huge area for which he was responsible, MacArthur commanded not only all US troops but also Allied troops, ships and aircraft, the latter comprising mostly Australian elements but also a few Dutch and sometimes British elements. The major organisational components of the SWPA were General Sir Thomas Blamey’s Allied Land Forces, Lieutenant General George C. Kenney’s Allied Air Forces and Vice Admiral Thomas C. Kinkaid’s Allied Naval Forces. Two major force were created within the SWPA for operational purposes in 1943: New Guinea Force under Blamey and the New Britain Force under Lieutenant General Walter Krueger, commander of the US 6th Army.
The latter was created in June 1943 'Alamo' Force to provide a command operating directly under the SWPA’s headquarters as the 6th Army was under Blamey’s Allied Land Forces. The 'Alamo' Force was thus independent of the Allied Land Forces, whereas the 6th Army was subordinated to it. MacArthur this had a major force under his direct command without any Australian input.
Early in 1943, however, MacArthur had too little of practically everything the SWPA’s Allied forces needed, and his position might be described as precarious. So when Major General William H. Rupertus’s battered 1st Marine Division was relieved at Guadalcanal, it was moved from the South Pacific Area to the South-West Pacific Area to provide MacArthur with a trained amphibious formation after it had been rested and rehabilitated. The division was not part of the Allied Land Forces in Australia, but held in headquarters reserve directly under MacArthur until it was assigned to the New Britain Force. As the arrival of fresh forces from the USA increased MacArthur’s strength, the creation of definite plans for forthcoming operations started to reveal marked variations in army and marine tactical thinking.
Throughout most of 1943, the reduction (later changed to the isolation) of Rabaul continued to preoccupy the thinking of the Joint Chiefs-of-Staff, and their concept of operations in western New Britain accorded with the overarching strategy of both extending and tightening the net around the Japanese stronghold area. This concept was incorporated in the ‘Cartwheel’ directive issued 29 March 1943, which visualised it as a part of a three-pronged offensive.
For the implementation of ‘Cartwheel’, the ‘Elkton’ plan was created for the joint employment of the forces of the South-West Pacific Area and the South Pacific Area. Its goal was seizure of bases in the area of New Britain, New Ireland, New Guinea and Solomon islands group, with New Guinea and the Solomon islands group named as the primary objectives, and New Britain and Rabaul as the final objectives. Within ‘Cartwheel’, Operation I (‘Chronicle’) was the occupation of the Kiriwina and Woodlark islands; Operation II (‘Postern’) the capture of Lae, Salamaua, Finschhafen, the Madang area and the Buin and Faisi area; and Operation III (‘Michaelmas’) the occupation of western New Britain and Kieta, and the neutralisation of Buka.
The New Britain operation incorporated a number of secondary aspects. The seizure of a foothold at the western end of New Britain island required control of the Vitiaz Strait and was seen as a desirable if not essential preliminary to an attack on the Admiralty islands to clear the way, in turn, for advances farther to the west along the coast of northern New Guinea, a project that was required if the South-West Pacific Area to remain in operation. Possession of the airfield on Cape Gloucester by US forces would effectively sever the Japanese supply route between Rabaul and New Guinea, and conceivably provide the base necessary to a ground assault on Rabaul.
At this time MacArthur had his headquarters at Brisbane in eastern Australia, with a forward command post at Port Moresby in south-eastern New Guinea, and Krueger had the headquarters of his 6th Army on Goodenough island in the D’Entrecasteaux islands group, some 20 miles (32 km) to the north of New Guinea’s eastern tip.
On 15 July MacArthur’s headquarters circulated the ‘Marfa I’ plan for the occupation of western New Britain to include the line linking Gasmata and Talasea. No units were mentioned, but the plan noted that ‘This operation must be economically conducted in order to conserve forces for the assault on Rabaul…’ It called for one regimental combat team to ‘neutralize’ Gasmata, followed by an attack in force on Cape Gloucester and then an advance to the east in the direction of Talasea in a series of shore-to-shore operations. The scheme of manoeuvre for Cape Gloucester provided that one regiment would be landed to the east and to the west of the airstrip, while artillery was landed farther to the west to provide fire support, and a parachute regiment was to be dropped in the airfield. The target date was 15 November, with the Gasmata landing made seven days earlier.
‘Marfa I’ was followed by the ‘Marfa II’ plan of 26 August, which ordered ‘Alamo’ Force to ‘seize the Cape Gloucester area and neutralize Gasmata…and establish control over Western New Britain to include the general line between Talasea and Gasmata, the Vitu Islands and Long Island.’ It also ordered ‘Alamo’ Force to prepare itself for involvement in an amphibious assault to take Rabaul. By 31 August, this planning had progressed to the point where the 1st Marine Division was alerted for movement to the north into advanced staging areas, in accordance with which three operational orders were issued on the above date. The divisional ‘special action report’ summarised this complex process: ‘Division Operations Orders were issued forming the AMOEBA Force…, the LAZARETTO Force…and the BACKHANDER Force…These forces were all a part of the ALAMO Force under command of Lieutenant General Krueger, U.S. Army, Commanding General, Sixth U.S. Army. The mission of the ALAMO Force was to occupy western New Britain to include the general line Gasmata-Talasea and by combined airborne and overwater operations to establish airdromes therein for subsequent operations against Rabaul.’
Reduced to its basic elements, the ‘Marfa II’ plan provided that the ‘Lazaretto’ Force, comprising Combat Team A (5th Marines) less its 3rd Battalion, would land at Gasmata on D-7; the ‘Backhander’ Force, comprising Combat Team C (7th Marines) plus a detachment of the divisional headquarters and reinforcing elements, would land on Cape Gloucester on D-day, to be followed on D+7 by the 503rd Parachute Regiment; the ‘Amoeba’ Force, comprising Combat Team B (1st Marines), the 3/5th Marines and all other uncommitted elements of the division, was to be held in reserve, the battalion for Gasmata and the combat team for Cape Gloucester. Also included in the reserve forces was Major General Edwin F. Herring’s 32nd Division. D-day initially remained 15 November, but was changed two weeks later to 1 December.
As initially promulgated, the ‘Marfa II’ plan triggered a number of objections from experienced marine divisional officers, who believed that the ‘Backhander’ Force was neither large enough nor sufficiently co-ordinated to handle the Japanese forces likely to be encountered on Cape Gloucester. In addition to a natural desire to keep the division intact, the planners argued against a three-way split on the grounds that it would not permit the landing of a sizeable force against a Japanese strength believed to be numerically equal or superior, well established and determined.
MacArthur’s command structure effectively rejected the marine objections, and in September the 1st Marine Division began its movement to its three different staging areas, namely Milne Bay in eastern New Guinea for Combat Team A led by Brigadier General Lemuel C. Shepherd, the assistant divisional commander, Goodenough island in the D’Entrecasteaux islands group for Combat Team B, and Cape Sudest near Dobadura in New Guinea for Combat Team C. The advance echelon of the divisional headquarters established itself on Goodenough island during 9 October, and nine days later received the ‘Alamo’ Force’s initial order, which attached Combat Team A to the Cape Gloucester Task Force, but left much to be desired from the marines’ point of view. It retained the essentials of the initial concept, namely the operation against Gasmata and the employment of a single regimental combat team at Cape Gloucester, supported by one parachute regiment. The mission of neutralising Gasmata was entrusted to the 126th Regimental Combat Team of the 32nd Division, but instead of being placed under direct divisional control, Combat Team A was grouped with the supporting garrison elements for Cape Gloucester. Worst of all, so far as the 1st Marine Division was concerned, Combat Team C was split into two separate assault forces.
The plan directed that Combat Team C, less one battalion landing team, land at Cape Gloucester on D-day, tentatively scheduled for 20 November, to be followed by the 503rd Parachute Regiment. The lone battalion landing team remaining would land at Tauali and march rapidly to the north in the direction of the airfield, sending a reconnaissance group through Aipati, Agulupella and Natamo. Combat Team B would move to Finschhafen on D-6 prepared to land (less one battalion landing team) in support of Combat Team C. The detached battalion landing team would be ready to seize Rooke and Long islands or to reinforce the Cape Gloucester units on Krueger’s order. Combat Team A was to remain at Milne Bay until ordered to move by Krueger.
The planning staff of the 1st Marine Division had from the start seen Cape Gloucester as the key to the entire situation as a result of its possession of a large airfield, which was also suitable for further enlargement, and also for its strategic location at the western tip of New Britain. The marine planners’ concerns were further increased as new intelligence indicated that the Japanese held the same view and were increasing their strength in that area to what might prove several times the maximum figure of 1,500 previously estimated, which would by sufficient to jeopardise success of the whole expedition as currently conceived.
Rupertus transmitted these concerns to Krueger on 3 November, and urged that Combat Team C be retained as a single combat entity. As alternatives, Rupertus suggested using elements from either the parachute regiment or Combat Team B for the Tauali landing while permitting Combat Team C to land as an entity in the eastern sector of Cape Gloucester.
The Gasmata project was the brainchild of Kenney, who wished to establish an air base on New Britain’s southern coast. The US Navy also wanted it for a PT-boat base in order to intercept barge traffic passing that way. But Gasmata was closer to Rabaul than to Dobadura and there was increasing evidence that it was a poor location for an airfield. By a time early in November, therefore, Kenney and his deputy, Major General Ennis C. Whitehead, had lost much enthusiasm for the concept, and on 21 November a conference between Krueger, Kenney, Rear Admiral Daniel E. Barbey (commanding the VII Amphibious Force) and Major General S. J. Chamberlin (MacArthur’s operations officer) recommended that Arawe be substituted as equally suitable for a PT-boat base.
This change was made on 22 November, and eight days later the Gasmata plan was cancelled and the new ‘Director’ Task Force (centred on the 112th Cavalry Regimental Combat Team) established for the attack on Arawe in order to ‘seize and defend a suitable location for the establishment of light naval facilities’.
The dates for the operations were now scheduled as 15 December for Arawe and 26 December for Cape Gloucester. While this latest iteration conceded the 1st Marine Division’s primary objection, namely the splitting of Combat Team C, the marine divisional staff was still unhappy with the planned scheme of manoeuvre. This called for the landing of one regimental combat team (7th Marines) to the east of the airfield, one battalion landing team (2/1st Marines) to the west of the airfield, and the dropping the 503rd Parachute Infantry in a large patch of tall, sharp-edged kunai grass some thousands of yards to the south-east, the three elements then converging on the target. As drawn on an operations map with neat blue arrows, this manoeuvre appeared feasible to students of tactics who had never seen the mountains, swamps and rain forest jungles of the South-West Pacific Area, but did not impress the jungle-experienced officers of the 1st Marine Division, who were fully aware of the difficulties of co-ordinating the movements of three widely dispersed forces in such terrain against an opposing force that probably outnumbered any one of them.
At a time early in December the 1st Marine Division received an unexpected measure of support when Kenney expressed his opposition to the use of paratroops in the operation on the grounds that it was intended to use piecemeal paratroop drops instead of a mass drop, that piecemeal drops would require innumerable flights of troop carriers, and that these flights would be required at a time when the Japanese would have had time to arrange a major fighter reaction.
On 14 December MacArthur visited the 1st Marine Division’s headquarters, and was told of the division’s concerns. On the following day the airborne element of the plan was cancelled and other changes made. The result was a revised operation based on a concentration of strength to provide decisive strength, and within this Combat Team B (less the 1st Battalion Landing Team) was removed from the task force reserve and committed to a landing immediately behind Combat Team C’s assault on the eastern beaches before passing through the newly established beach-head line to attack westward toward the airfield. The new scheme retained the secondary landing on the western shore of New Britain by the 21st Battalion Landing Team, whose task now became defensive inasmuch as it was to block Japanese reinforcement of the airfield area from the south and cut off the Japanese garrison’s line of retreat in that direction. Perhaps equally important for the 1st Marine Division was that Combat Team A was designated as the task force reserve, to be brought forward from Milne Bay to Cape Sudest, where two battalions would be trans-shipped ready for rapid reinforcement of the Cape Gloucester operation at Rupertus’s request.
Thus the definitive plan became effective just 11 days before the scheduled landing date of ‘Backhander’, and on the very day that the newly conceived Arawe operation began as ‘Director’.