| Trapped — rifle sights lined on the entrance to an Okinawan cave, Marines await the results of an explosive charge to pick off any Japs who attempt to escape. These bitterly contested cave positions formed the Japanese “Little Siegfried Line,” defending the capital city of Naha. All Marines sight-in on the mouth of a cave into which an explosive charge had been thrown, and wait to see if any enemy soldiers will try to escape. This is 1 of the many bitterly contested cave positions found in numerous ridges and hills. The terrain of terraces, steep escarpments and rugged ravines approached perfection for defense. The Japanese had carved the limestone and coral of each commanding hill there into a kind of land battleship. Outdoing themselves in excavation and construction, the Imperial Japanese 32nd Army had fashioned “defensive masterpieces” largely impervious to the fire of the real United States Navy battleships offshore as well as of the United States Army land artillery and United States Army Air Force bombers. Many of the Japanese positions were contiguous or provided with protected access from 1 to another. Where possible, they had been tunneled with bends just inside the entrances to limit the fire entering the interiors. A single sector of well less than half a square mile would be found to contain 16 hidden light mortars, 83 light machine guns, 41 heavy machine guns, 7 antitank guns, 6 field guns, 2 mortars and 2 howitzers. The most extensive works were in the high ground protecting Shuri Castle, which would have been difficult to take even with less shrewd and elaborate fortifications. Centuries of Okinawan kings had built forts on those best defensive sites in the south-central area. “The Japanese,” Major Roy E. Appleman (April 10, 1904 – December 12, 1993), Master Sergeant James M. Burns (August 3, 1918 – July 15, 2014), Captain Russell A. Gugeler (December 25, 1912 – August 8, 1985) and Lieutenant Colonel John Stevens (1911 – 2001) wrote in “Okinawa the Last Battle,” that the Japanese “took full advantage of the terrain to organize defensive areas and strongpoints that were mutually supporting, and they fortified the reverse as well as the forward slopes of hills. Artillery and mortars were emplaced in the caves and thoroughly integrated into the general scheme of defensive fire.” Shuri Castle was the keystone of Imperial Japanese Army Major General Mitsuru Ushijima’s (July 31, 1887 – June 22, 1945) strategy of a war of attrition. Even 16 inch (406 millimeter) naval shells could not disturb the deep, vast tunnel beneath it — almost 1,300 feet long, with blower-assisted ventilation shafts — that served as Imperial Japanese 32nd Army headquarters. Shuri Castle stood on a high knob near Naha City’s southern edge. East and west from there, the line was carved and constructed across the island’s full 12-mile width. Anchored by the Asakawa River on the west coast, the Shuri heights in the center and a hill mass at Yonabaru Town on the east (Pacific) coast, this mighty system of artfully placed fortifications was like a Corregidor for the bulk — perhaps 70,000 troops — of the 32nd Army. For all the late start, logistical difficulties, interference by American air raids, loss of the 9th Division to transfer to Taiwan and other setbacks, the defenders had built their most formidable positions of the Pacific War on terrain best suited for them. Americans who inspected the works after the battle – young men, who in 1945, knew little of the Japanese capacity for toil – could hardly credit that they had been completed in under a year. “I couldn’t believe those underground forts,” 1 Marine said, speaking for thousands. “Two-tiered quarters, running water, everything beautifully engineered — it was like ships inside the hills. That’s why you never saw a Jap[anese] most of the time: they’d be bombed, bombarded, napalmed — and safe inside those thousands of caves. And caves with mouths so small you wouldn’t see them until you were almost right on them and they started shooting. Bingo!” In and out of the caves, hidden positions were placed for the best flat-trajectory fire directly on areas where attackers would have no cover or concealment, and for the best protection, often in compartments radiating from the tips of trenches. Major and minor strongpoints were integrated to provide intersecting, interlocking fields of fire for artillery, mortar, machine gun and small-arms fire, and the vantage points from the heights facilitated their coordination for rare accuracy, economy and effect. Mounted on tracks, artillery pieces could be rolled to the mouth of their camouflaged cave or emplacement, fired once or twice and rolled back out of sight, some around a bend, before their positions could be fixed — as in the north, but with 30 times more guns. Little zeroing in was required because everything had been pinpointed on a tight grid. In short, every boulder, depression and clump of trees was covered. The attackers would have to advance fully exposed; the defenders were relatively safe so long as they stayed hidden. A network of trenches, galleries, caves and tunnels — some complexes almost 2 miles long — featured the added advantage of exits at both ends and sometimes on the flanks of the hills. Careful “engineering” of unit deployment allowed limited resources to be shifted and concentrated through that network to meet battle needs as they developed. All this, in addition to improved living quarters in the larger fortifications, was the best that Colonel Hiromichi Yahara (October 12, 1902 – May 7, 1981), operations officer, and General Isamu Chō (January 19, 1895 – June 22, 1945), chief of staff, had been able to devise and demand from their troops, indefatigable diggers and movers of earth, during the year of preparation. Fine brains managing prodigious labor had produced a defensive tour de force. Military histories rightly dwell on Ushijima’s “maze of caves, interconnecting tunnels well stocked with grenades, with approaches well mined and covered by barbed wire (and] supported by fierce mortar, artillery and machine gun fire,” but it may be enough to say that Americans began speaking of “the Little Siegfried Line” and learning that it was manned by an enemy as formidable as the Germans. By early May 1945, the general nature of the Japanese resistance on the island’s southern 3rd had become clear, and it was the worst possible kind for an offensive campaign, fought entirely from skillful underground complexes under commanders whose ultimate purpose was to die in combat. The American optimism of early April was replaced by an acceptance that Okinawa would be no exception to the Japanese rule of savage fighting for every rise, hill, tomb and cave. On the contrary, it promised to be the war’s harshest confirmation of the rule until the even bloodier fighting that would have to follow on the mainland. Against such opposition, it seemed sensible to take 1’s time, blasting and blasting again with every available shell before advancing with bodies — which is what the 40,000 troops of the Army’s 7th and 96th Divisions had been doing almost since L-day. While the 6th Marines were racing for Okinawa’s north, the Army was bearing the brunt of the warfare on a hard grind south. The 1st serious barrier, the northernmost from Shuri Castle, stood only a few miles below the landing beaches. 5 days after L-day, strongpoints there slowed the advance of many Army units to less than a crawl. They were forced to attack Cactus Ridge and the Pinnacle again and again before taking them, with heavy casualties. Although hills and rises were identified by numbers on the map, the customary American nicknaming began immediately. The Pinnacle, atop which Commodore Matthew C. Perry’s (April 10, 1794 – March 4, 1858) party may have planted an American flag 92 years earlier, was only some 40 feet high; it served as an introduction to rises that seemed piddling until the attackers’ approach prompted fire from concealed caves, bunkers and a collection of stone and concrete tombs converted to pillboxes. The tactical meaning of interlocking fire from adjacent rises and hills became clear to everyone. It left no weak point to attack. Those small fortresses, and even smaller ones in between, had given just a taste of what lay ahead. On April 9, 2 battalions of the 96th Division’s 383rd Infantry Regiment launched a major attack on seemingly unimpressive Kakazu Ridge, which actually anchored a major defensive line some 4 miles north of the main Shuri Line. Its defenders repulsed powerful thrusts. Soon both Army divisions were engaged. It took 8 days and over 1,100 casualties to advance 6,000 yards. It took the other 3 days of intense attack to capture a single small hill in a line studded with them. Kakazu Ridge remained untaken. | |
| Image Filename | wwii1850.jpg |
| Image Size | 1.73 MB |
| Image Dimensions | 3821 x 2917 |
| Photographer | |
| Photographer Title | United States Marine Corps |
| Caption Author | Written or Adapted by Jason McDonald |
| Date Photographed | May 25, 1945 |
| Location | |
| City | |
| State or Province | Okinawa |
| Country | Ryukyus |
| Archive | Library of Congress |
| Record Number | LC-USZ62-110863 |
| Status | Caption ©2026 MFA Productions LLC Please Do Not Duplicate or Distribute Without Permission; Image in the Public Domain |
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