Battle of Wakde

The Battle of Wakde (Operation Straight Line) was part of the New Guinea campaign of World War II. It was fought between the United States and Japan from 17 May 1944 to 21 May 1944 in Dutch New Guinea (now Papua, in Indonesia). The operation involved an assault on the Japanese-held Wakde island group by a reinforced US infantry battalion, which was transported from a beachhead the Allied troops had established around Arara, on the mainland, the previous day. Following the capture of the island, fighting on the mainland continued until September as Allied troops advanced west towards Sarmi. In the aftermath, the island's airbase was expanded and used to support operations around Biak and in the Marianas.

Wakde is an island group, which lies two miles off the northeastern coast of Western New Guinea. It consists of two islands: Insoemoar and Insoemanai. Of these, Insoemoar is the largest, although it is only 1.5 miles (2.4 km) long, and lies on the outer side of the smaller island, to the northeast. It is largely flat and at its largest point is 3,000 feet (910 m) wide. On the mainland shore, the nearest village at the time of the battle was Toem. At the time of the battle, the area's strategic importance lay it is proximity along planned Allied avenues of advance through the southwest Pacific toward the Philippines, offering the Allies an airfield for land-based aircraft to attack facilities at Biak Island, about 180 miles (290 km) away.

Initial Allied plans had called for the capture of Sarmi on the mainland, but aerial reconnaissance had later shown that it was unsuitable for heavy bombers. As a result, the Allied commander, General Douglas MacArthur had decided to focus on the capture of Wakde instead, followed by Biak. Allied aircraft operating from this area could also be used to support operations in the central Pacific, including those operations planned as part of the Mariana and Palau Islands campaign. The Allies were able to move against Wakde after the successful completion on 26 April of the Battle of Hollandia, about 120 miles (190 km) to the east. The discovery that the airfields around Hollandia, on the Sentani plain, could not support heavy bombers, accelerated Allied plans to secure Wakde. For the Japanese, the area offered an important line of defense and since late 1943 they had begun developing the area, installing supply dumps and an airfield, and moving in sizeable concentrations of troops.

The area had been occupied by the Japanese in 1942 and an airfield had been developed on Insoemoar, consisting of a coral runway as well as buildings and staging facilities. An anchorage suitable for flat or shallow-bottomed vessels lay on the southern side of the larger island, with a small jetty and an area suitable for a landing beach. Along the mainland, to the west, the Japanese were in the process of constructing an airfield around Maffin Bay (west of the Tor River) and had also built an airstrip at Sawar, about halfway between Maffin Bay and the village of Sarmi. The Japanese had installed antiaircraft guns around the three airfields, and had around 11,000 troops in the Sarmi–Sawar–Maffin area, centered around Sarmi where Lieutenant General Hachiro Tagami's 36th Division had established a command post.

On Wakde itself, there were about 800 Japanese troops, including a company of infantry from the 224th Infantry Regiment, as well as naval troops, support personnel and a weaponless antiaircraft battery from the 53d Field Antiaircraft Artillery Battalion. There were several 75 mm artillery pieces, some mortars and machine guns, and over 100 bunkers. Japanese air assets available to support the defense of Wakde and Sarmi were estimated at 282 fighters and 246 bombers, but the force was in the process of reorganization and was off balance; it was assessed that around half this force would remain in the Philippines and Palaus.

Initially, Allied planners had intended to launch the operation on 15 May; however, delays in concentrating logistics and shipping assets resulted in the Allies postponing the operation by several days. Nevertheless, the necessity to conform with plans in the central Pacific meant that it could be carried out no later than 17 May, with operations to capture Biak scheduled to take place 10 days later using most of the same landing craft. The beach frontage on Wakde was considered too narrow to support a full regimental combat team; as a result, it was decided to carry out the operation in three phases. The first phase would entail a landing on the mainland opposite the islands. This would be followed in phase two by a "shore-to-shore" operation across the bight to capture Insoemanai, to secure a base of fire to support the final phase of the assault on Insoemoar.

The main combat forces assigned to the Wakde–Sarmi operation were drawn from Brigadier General Jens A. Doe's 163rd Regimental Combat Team, consisting of 7,800 men, of which about 1,500 took part in the landing on Wakde. This unit had previously taken part in the Landing at Aitape and had been relieved there by the 32nd Infantry Division on 4 May. After embarking at Aitape on 15 May, the troops were initially transported to Hollandia on 16 May in preparation for the operation. Meanwhile, Allied aircraft mounted airstrikes around the target area throughout late April and into May. The naval forces assigned to the operation were detached from Rear Admiral William Fechteler's Task Force 77. These forces were designated the Eastern Attack Group and were commanded by Captain Albert G. Noble, and consisted of three fire support groups, with two heavy cruisers, three light cruisers and 20 destroyers. Fourteen other support vessels were allocated included minesweepers, submarine chasers and several landing craft armed with rockets. The landing craft carrying the assault troops were operated by the 542nd Engineer Boat and Shore Regiment, of the 2nd Engineer Special Brigade.

The pre-invasion naval bombardment allocated to support the first phase of the operation involved two cruiser forces: Task Force 74 and Task Force 75. The first force was commanded by British Rear Admiral Victor Crutchley, and consisted of four Australian ships – the cruisers Australia and Shropshire and the destroyers Warramunga and Arunta – and two US destroyers, Mullany and Ammen. Task Force 75 was commanded by US Rear Admiral Russell Berkey, and consisted of the cruisers Phoenix, Boise and Nashville. While Crutchley's force shelled the mainland around Sawar and Sarmi, Berkley's ships hit Wakde. Ten destroyers under Captain Richard Stout also fired upon targets between Toem and Maffin Bay.