Although by 20 May the American troops were still short of the line set by Tenth Army as the point of departure for a general offensive, there was no time to spare in launching this offensive. Admiral Turner was somewhat impatient because of the heavy naval losses, particularly in picket ships. On 4 May Brig. Gen. Elwyn Post, Tenth Army Chief of Staff, had declared that the situation was serious and that immediate action was imperative.{383}After the failure of the Japanese offensive, General Buckner felt that the moment was opportune because the enemy had used almost all his fresh reserves in the counterattack; both his divisions were in the front lines and the 4th Independent Mixed Brigade also had been partly committed.{384} Accordingly, General Buckner on 9 May ordered a coordinated Tenth Army attack for the 11th.
With both corps now on the line, Tenth Army on 7 May assumed direct control of operations on the southern front for the first time. By 11 May the III Amphibious Corps in the north (consisting of the 6th Marine Division and Corps troops) had been relieved by the 27th Division and had moved into position on the right of the southern front. The Corps assumed control again of the 1st Marine Division, which had been attached to XXIV Corps since the latter part of April. The XXIV Corps' zone of action now extended eastward from the 1st Marine Division boundary to Yonabaru. From west to east, the 6th Marine Division, the 1st Marine Division, the 77th, and the 96th occupied successive positions on the line. The 7th Division was in XXIV Corps reserve, enjoying a period of rest and rehabilitation.
The plan of attack called for Tenth Army to renew the assault on the Shuri defenses with its two corps abreast, III Amphibious Corps on the right, XXIV Corps on the left. The initial scheme of maneuver was an envelopment of Shuri by the Marine divisions on the west and the Army divisions on the east, while a strong holding attack was maintained in the center.{385} The Tenth Army staff believed that the Japanese positions were weaker on the right and that the fresh Marine divisions had a chance for a quick break-through on that flank. Moreover, the terrain was more favorable along the western coast. The wide flanking maneuver around Shuri that later developed was not projected in the original plans. General Buckner explained on 10 May that there would be nothing spectacular. He added:
“It will be a continuation of the type of attack we have been employing to date. Where we cannot take strong points we will pinch them off and leave them for the reserves to reduce. We have ample firepower and we also have enough fresh troops so that we can always have one division resting.”{386}
The initial order for the attack provided for a 30-minute general preparation by the artillery just before the ground attack. This provision was revoked two days later in favor of pinpointing of targets. The new order stated that "the maximum practicable number of known enemy guns and strong points will be destroyed or neutralized" prior to the infantry assault. This change resulted, in all probability, from recognition of the failure of the mass preparation for the attack of 19 April. The elaborate system of Japanese underground positions across the entire front made it necessary to use precision fire, hitting each cave entrance.{387}
In preparation for a renewed American attack the Japanese bolstered their Shuri defenses. Ready at last to commit almost all his reserves to action, General Ushijima ordered that "the Army will immediately move its main strength into the Shuri area." He established a central defense zone with his front lines running from a point north of Asato on the west coast, through Wana and the high ground near Ishimmi, to the east coast just north of Conical Hill. Aware of the entrance of the 6th Marine Division on the west, he shifted his forces for an iron defense on both his flanks. General Ushijima ordered roads and bridges to be destroyed east of Naha. His continued fear of an attack behind Japanese lines by American parachute troops, however, restrained him from bringing all available forces up to the front.{388}
Map No. 40: Tenth Army Advance
The attack launched on 11 May, although coordinated initially along the entire front, soon broke down into a series of intense battles for particular points with the western, central, and eastern sectors presenting relatively distinct situations. At many places the American efforts were merely an intensification of assaults that had begun on previous days. For ten days of continuous fighting, from Sugar Loaf on the west coast to Conical Hill on the east, the Japanese, except for local and relatively minor retreats, held tenaciously to their long-prepared positions. Finally, on 21 May, after some of the bitterest action of the battle of Okinawa, the American forces were to seize the eastern slope of Conical Hill, close to the east coast, and thereby to make an opening in the enemy lines which permitted an attempt at envelopment.
On 8 May the 22d Marines, 6th Marine Division, relieved the 7th Marines, 1st Marine Division, on the bluffs north of the Asa River. The enemy held positions south of the Asa, which was too deep to ford at the mouth and which had a bottom too soft to support any type of vehicle. The enemy-held ground rose gently to the horizon 2,000 yards away. To the west barren coral ridges formed a barrier to the sea; to the south a long clay ridge dominated the road to Naha; to the southeast a group of low grassy hills, set close together, commanded the ground between the Asa River basin and the Asato River corridor. On the east were the rough folds of Dakeshi Ridge, Wana Ridge, and Wana Draw, positions toward which the 1st Marine Division was driving.{389} (See Map No. 40.)
Maj. Gen. Lemuel C. Shepherd, Jr., commander of the 6th Marine Division, had warned his troops that the battle in southern Okinawa would be different from anything they had previously encountered in the Pacific. In a training order read twice by every platoon leader to his men, he described the enemy's intelligent use of artillery, his ample supplies, his defensive line "which cannot be breached by simple frontal attack without heavy losses," and his willingness to counterattack by every available means. General Shepherd urged his commanders and troops to take advantage of cover and camouflage, to use maneuver in outflanking the Japanese rather than to try to "outslug" them, and to keep driving. "Your enemy can't think as fast as you can and he is no match for a determined aggressive Marine who has confidence in himself and his weapon."{390}
The 22d Marines began crossing the Asa estuary in the early hours of 10 May over a footbridge completed during the night. An enemy suicide squad destroyed the bridge with satchel charges after the first three companies had crossed, but other marines reached the south bank by wading. During the morning the troops advanced into the town of Asa against steadily increasing resistance. Movement west of the town was difficult in the confusion caused by heavy fog and smoke. Direct fire from self-propelled 105-mm. howitzers and LVT's supported the attack. Despite heavy enemy artillery fire and strong local counterattacks on the infantry, the 22d Marines had established by dark a "beachhead" 350 yards deep and almost a mile wide. (See Map No. 39.)
During the night of 10-11 May the 6th Marine Division engineers, working under fire, laid across the Asa a Bailey bridge which enabled tanks and other heavy weapons to support the attack. The marines advanced under almost continual artillery fire delivered from the western face of Shuri Heights, where the enemy had excellent observation of the coastal area. Japanese infantry opposition was well coordinated with this fire. A company commander of the 1st Battalion, 22d Marines, led a squad up to the summit of a strongly defended hill 800 yards south of Asa, but all his troops were killed or wounded in the assault except the flame-thrower man. A concentration from the main battery of a fire support ship broke loose great blocks of coral from the top of the hill and rolled them down the face, but without much damage to Japanese positions. An infantry charge by Company C, closely supported by tanks, finally won the hill. Although Company C was now reduced to eighty men, the marines clung to the hill in the face of counterattacks.
On the regimental right (west) the 3d Battalion seized a cliff on the coast north of the town of Amike by a tank-infantry-flame-thrower assault late in the afternoon. This advance placed the Marines on the northern outskirts of Amike overlooking the devastated city of Naha, capital of the Ryukyus. Had this city, the largest in the islands, been the objective of Tenth Army the 6th Marine Division would have held an excellent position from which to capture it. Since Naha was not their objective, however, the marines who reached the north bank of the Asato near its mouth simply consolidated their position during the next two weeks, sending patrols into Naha, while the marines to the east continued to press in on the flank of Shuri.
WEST FLANK ZONE, where the 22d Marines, 6th Division, crossed Asa River toward Naha. (Photo taken 5 May 1945).