The Continuing story of the 4th Marines
The size and scope of Operation Iceberg —the Battle for Okinawa, given the island’s size and terrain, was massive. Iceberg included the Tenth US Army’s XXIV Corps (four infantry divisions) and the III Marine Amphibious Corps (1st, 2nd, and 6th Marine Divisions), the Fifth US Fleet (Task Force 58, 57, and the Joint Expeditionary Force), involving a combined force of 541,000 personnel (250,000 of which were combat troops). Tenth Army was uniquely organized in the sense that it had its own tactical air force (joint Army-Marine Corps aviation).
The Tenth Army faced 96,000 Japanese and Okinawan belligerents. Between 14,000 to 20,000 Americans died on Okinawa; between 38,000 to 55,000 Americans received serious wounds. Japanese losses were between 77,000 to 110,000 killed with 7,000 captured alive. Approximately half of the entire civilian population living on Okinawa were killed out of an estimated island-wide population of 300,000.
Iceberg was the largest amphibious assault in the Pacific War. The 82-day battle had but one purpose: seize the Kadena air base for Operation Downfall, the planned invasion of the Japanese home islands. The Japanese put up one hell of a fight in their defense of Okinawa but in doing so, they sealed their own fate: the ferocity of the Japanese Imperial Army convinced Washington politicians that dropping its new secret weapon (an atomic bomb) was far better than trying to take the Japanese home islands by force of arms —and costing the Americans an (estimated) additional one-million casualties.
The landing force demanded a massive armada of ships. The Navy would have their hands full with Kamikaze aircraft from mainland Japan. The 6th Marine Division’s mission was to capture Yontan airfield in the center part of the Island. The first assault wave came ashore at 0837, and the 4th Marines (less its 2nd Battalion, held in reserve) was among the first units to hit the beach. What shocked the Marines was that they encountered no resistance from Japanese defenders. Accordingly, the American advance was rapid; significant territorial gains were achieved on that first day. In the absence of Japanese resistance, 2/4 came ashore at noon and rejoined the regiment. Yontan was taken ahead of schedule and then, according to the game plan, the 6thMarDiv turned north. Marine progress continued unimpeded until 7 April when the Marines encountered Japanese defenders on the Motobu Peninsula.
The defense of this peninsula included several Japanese obstacles along the Marine’s likely avenues of approach. Terrain favored the Japanese. Mount Yaetake formed the core of the Japanese defense. The mission of pacifying Mount Yaetake was assigned to the 4th Marines, reinforced by 3/29. The 22nd Marines and the balance of the 29th Marines moved to seal off the peninsula. There is no sense in having to fight the same enemy twice.
The 4th Marines attack commenced on 0830 on 14 April. 2/4 and 3/29 made the preliminary assault on a 700-foot ridge. The Marine advance was bitterly contested until 16 April; it was a classic search and destroy mission but the Japanese weren’t going quietly. On 16 April BLT 3/4 was brought into the line. Marines from Company A and Company C boldly charged through the enemy’s heavy barrage of mortar and machine gun fires to seize the crest by mid-afternoon. Once the Marines secured and consolidated their positions, the mission continued to eliminate pockets of resistance. Combined, the two-company assault resulted in the loss of 50 Marines killed and wounded.
The 6thMarDiv pushed on and the peninsula was pacified on 20 April. Organized resistance in northern Okinawa ended on 21 April 1945. Major General Lemuel C. Shepherd, Jr., commanding the division, declared his sector secure and available for further operations. In the southern sector of the Island, all American progress came to a halt at the Shuri Line .
General Buckner ordered III Amphibious Corps (Lieutenant General Roy Geiger, commanding) to redeploy his Marines to the left of XXIV Corps; the US 27th Division replaced the 6thMarDiv in its mopping up operations. Shepherd’s Marines were in place by 6th May. Buckner ordered another advance and the 6thMarDiv was tasked with capturing the city of Naha. 4th Marines began their engagement on 19 May after relieving the 29th Marines, who by this time were fought-out. It was a brutal form of war —up close and personal: Marines had to dislodge the Japanese in hand to hand combat. By the time the 4th Marines reached Naha, they were ready to come off the line and were replaced by the 29th Marines.
On 4 June, the 4th Marines assaulted the Oroku Peninsula, the location of the Naha airfield. It was an amphibious assault involving BLTs 1/4 and 2/4 under a blanket of naval gunfire and field artillery support. BLT 3/4 came ashore a few hours later as the reserve force. That afternoon, the 29th Marines came ashore and lined up next to the 4th regiment. It was a slug-fest with a well-entrenched enemy; the battle lasted for nearly two weeks. Torrential rains and thick mud hampered the progress of Marines —mud and slime not even tracked vehicles could penetrate. On 12 June, the outcome of the battle became self-evident. The Japanese continued fighting, of course, but their back was to the water and there was no possibility of escape. By this time, the Marines weren’t keen on taking prisoners. The 22nd Marines closed the back door by moving into a blocking position at the base of the peninsula. The Japanese had but two choices: surrender or die. Most opted for the second option. General Shepherd informed III Amphibious Corps on 13 June that the peninsula belonged to the American Marines.
Following this battle, 6thMarDiv proceeded south to link up with the 1stMarDiv in the final engagement of the battle. 4th Marines returned to the front on 19 June and commenced their advance on the next morning. The Marines encountered some resistance, but not much —the Japanese were fought out, too. All organized resistance ended on 21 June 1945. The 4th regiment’s casualties in the Battle of Okinawa exceeded 3,000 killed and wounded. With Okinawa in American hands, the 4th Marines headed back to Guam for rest, retraining, and refit. Everyone was thinking of the planned assault on the Japanese home islands; no one was happy about such a prospect.
US bombing of Hiroshima and Nagasaki took place in early August. I’m not sure most Marines knew what an atomic bomb was back then, but even among those who might have had an inkling I doubt whether many were remorseful. Planners began to consider final preparations for occupation. With Japanese acceptance of the terms of surrender on 14 August, Task Force Alpha began to organize for seizure of key Japanese positions, including the naval base at Yokosuka in Tokyo Bay. The main element of Task Force Alpha was the 4th Marine Regiment. The decision to assign the 4th Marines to this duty was a symbolic gesture to avenge the capture of the “old” 4th Marines on Corregidor.
The US 4th Marine regiment was the first American combat unit to land on the Japanese mainland.
As the Marines transitioned from transport ships to landing craft at 0430 on 30 August, they no doubt expected treachery from their war time foe. No matter —the Marines were prepared for any eventuality. First ashore was BLT 2/4, which landed at Cape Futtsu. The Marines were the first foreign invasion force ever to set foot on Japanese soil. Upon landing, the Marines quickly neutralized shore batteries by rendering them inoperable. After accepting the surrender of the Japanese garrison, BLT 2/4 reembarked to serve as a reserve force for the main landing at Yokosuka. BLTs 1/4 and 3/4 landed at around 0900; 3/4 seized the naval base, and 1/4 took over the airfield. Demilitarization of all Japanese installations was initiated as a priority; it would be better not to have loaded weapons in the hand of a recently conquered army. For all of that, all landings were unopposed. Japanese officials cooperated with the Marines to the best of their ability.
Task Force Alpha was disbanded on 21 September 1945 and all 6thMarDiv units were withdrawn from Japan —except one. The Fourth Marines were placed under the operational control of the Eighth Army and the regiment was assigned to maintain the defense of the Yokosuka naval base. This included providing interior guard and the disarming Japanese (who appeared in droves to surrender their weapons). This duty continued until November. President Truman had ordered rapid demobilization of the US Armed Forces. Operational control of the 4th Marines passed from Eighth Army to Fleet Marine Forces, Pacific on 20 November. At the end of the month, BLT 1/4 was ordered to proceed to Camp Pendleton, California, where it was deactivated on 29 December 1945. The regiment’s remaining elements (except for the regimental headquarters and BLT 3/4) departed Japan on 1 January 1946. These units were deactivated at Camp Pendleton on 20 January. BLT 2/4 was deactivated on 31 January 1946. BLT 3/4, still in Japan, was deactivated at Yokosuka and these Marines formed the core of a newly created 2nd Separate Guard Battalion. They would remain in Japan to guard the naval base.
Headquarters 4th Marines departed Japan on 6 January for Tsingtao, China. After four years, The China Marines had returned from whence they came. In China, 4th Marines headquarters was re-attached to the 6th Marine Division, but the regiment really only existed on paper until 8 March 1946. On that date, all three battalions and weapons company were reactivated in China, a matter of shifting personnel from the 22nd and 29th Marines, which were deactivated.
Occupation duty in China presented an uneasy situation for everyone concerned. Truman wanted a smaller military, and he wanted it now, even as Marines confronted an aggressive Communist Chinese Army in North China. The 6th Marine Division was deactivated on 31 March. All remaining Marine Corps units in China were re-organized as the 3rd Marine Brigade. The core element of the 3rd Brigade was the 4th Marine Regiment. Initially, 4th Marines was the only Marine Corps regiment to retain its World War II combat organization of three battalions. Then, on 10 June 1946, the 3rd Marine Brigade was also deactivated; operational control of the 4th Marines was transferred to the 1stMarDiv.
Truman’s reductions kept the Marine Corps in a constant state of flux. In the second half of 1946, the 4th Marines (less its 3rd Battalion) was ordered back to the United States. BLT 3/4 was placed under the operational control of the Commander, Naval Port Facilities, Tsingtao. Meanwhile, the regiment’s arrival at Camp Lejeune, North Carolina on 1 October was the first time the 4th Marines had set foot inside the United States in twenty years. As most of its veterans were discharged or reassigned, the regiment was once more reduced to a paper tiger. In May 1947, the 1st Battalion was reactivated. BLT 3/4, which was still in China was deactivated. In November 1947, 4th Marines lost its traditional structure and became a four-company size organization: Headquarters Company, Company A, Company B, and Company C. This significantly reduced structure remained in place for the next two years. Even so, these rifle companies participated in a number of post-War exercises in the Caribbean.
In September 1948, what was left of the 4th Marines was again sent overseas aboard vessels of the 6th Fleet in the Mediterranean Sea. Cold War antagonism between the Soviet Union and United States threatened to erupt into a full-scale war. By this time, President Truman may have realized that downsizing the US Department of Defense  while at the same time challenging the power of the Soviet Union wasn’t a very good idea. Suddenly realizing the ominous consequences of a Soviet-dominated Europe, Truman began sending military and economic aid to nations menaced by Communist aggression. Truman also decided to maintain a US presence in the Mediterranean to help ease the pressure on such countries as Greece and Turkey. In furtherance of this policy, the Marine Corps maintained a battalion landing team (BLT) as part of the Mediterranean fleet. The 4th Marines was re-activated from this BLT beginning in September 1948 and lasting until January 1949. America’s “show of force” included a landing at Haifa, Palestine in October. This detachment was ordered to proceed to Jerusalem to perform temporary guard duty at the American Consulate.
A few months after returning to the United States, the 4th Marines deployed to Puerto Rico for training exercises. The regiment was once again deactivated on 17 October 1949. Less than one year later, the military weakness of the United States along with other Truman administration blunders encouraged the North Koreans to invade the Republic of South Korea.
Next week: From Harry Truman’s War to the Streets Without Joy
- Organization of the United States Marine Corps, Marine Corps Reference Publication (MCRP) 5-12D. Washington: Headquarters, U. S. Marine Corps, 2015.
- Santelli, J. S. A Brief History of the Fourth Marines. Washington: U. S. Marine Corps Historical Division, 1970
 The Shuri-Naha-Yanabaru Line was a defensible series of positions held by the Japanese Imperial Army. It was so formidable, in fact, that during the contest, Marine Corps Commandant suggested that Tenth Army commander General Simon B. Buckner consider using the 2ndMarDiv in an amphibious assault on the southern coast of Okinawa, thereby outflanking the Japanese defenses. Buckner rejected the proposal, which left only one strategy: frontal assault.
 The Department of Defense was created through the National Security Act of 1947, a major restructuring of the US military and intelligence agencies. This act merged the War Department (renamed as Department of the Army) and Navy Department into the National Military Establishment, headed by the Secretary of Defense. It also created the Department of the Air Force and United States Air Force and established the United States Marine Corps as a separate service under the Department of the Navy.