Few units hold the distinction to have fought an enemy of the United States on U.S. soil. The 7th Infantry Division is one of those few.
During World War II, the United States experienced something that it had not experienced since the turn of the 20th century: it was attacked on its own home soil and even had some of that soil taken away. The WWII story of the 7th begins on the island of Attu, Alaska as part of the Aleutian Islands Campaign (which went from June 1942 to August 1943, with fighting on Attu May 1943), where they had some of the first units to offensively fight the ground forces of the Imperial Japanese who had invaded and captured the islands in 1942. Consequently, Bayonet Division units were also some of the last to fight the Japanese. What began in Alaska in 1942 would end a world away on an island called Okinawa three years later.
Okinawa: an island of strategic significance
In 1945, few had ever heard of Okinawa, but control of that island was critical to the success of Operation Downfall, the operational code name for the invasion of Imperial Japan. Okinawa had several fully constructed crushed coral airfields which could handle any current U.S. aircraft, making the island itself was an ideal location for a staging area for a mainland invasion of Japan. The 7th Division was designated as one of seven divisions chosen to be a part of the Tenth (X) Army, the combined joint force that would invade Okinawa (Operation Iceberg). Becoming a part of the largest amphibious invasion of WWII, the 7th was tasked first with the seizure of one of the major airfields on Okinawa (known today as Kadena Air Base), and then continue their drive across the width of the Okinawa. Once they arrived to the opposite shore side, the 7th was to move southward along the coastline.
It was commonly believed that the seizure of the Kadena Airfield would take several days from L-Day (or Love Day) on April 1, 1945 (intelligence predictions for the seizure of the Kadena Airfield was L+10). American intelligence based their predictions of the Okinawan defenses from their experience nearly everywhere else in the Pacific Theater. This meant they expected the American forces would be hit hard as they landed and would have a hard fight for every meter of land. These predictions were not without merit. After all, nearly every island U.S. forces invaded previous to this planned invasion were met on the beach with hard resistance.
However, this was not the case on April 1, 1945 as American forces came ashore on Okinawa. Imperial forces had laid one more surprise for them. The leadership of Imperial Japan knew that invasion of the home islands was now inevitable, which meant that for both Iwo Jima and Okinawa something different was in order. To give the home island enough time to prepare for the American invasion, both Okinawa and Iwo Jima operated defenses in depth, and planned for the islands to be massive delaying actions against the Americans. American intelligence did not predict that the Imperial Army would not meet them at the beach, nor could they predict where or how they would be met by a carefully planned defense in depth further south on Okinawa. In short, one could classify Okinawa as an intelligence failure.
At first, surprisingly unopposed
During the landing, the 7th Division, along with every other unit in the X Army, landed completely unopposed. This was different from the intelligence report which predicted up to 60% casualties per wave of the invasion. The 7th would come ashore at Beach Orange One and Beach Orange Two (today Kadena Marina) with roughly 20,000 soldiers, placing them less than a hundred meters from Kadena Airfield. As the 7th moved ashore, to their surprise they encountered no resistance. In fact, the airfield was abandoned. What the 7th found were Ohka planes (suicide bombers) left in hangers, fortifications (pill boxes), command buildings, and a plethora of supplies – all unmanned and unguarded. The 7th Division would not meet the enemy in direct combat until L+5.
The 7th achieved its primary landing objective within hours after landing instead of the predicted days, and before the end of L-Day, they had had reached the eastern shore of Okinawa. The 7th Division would not even engage the enemy force until L+5 (April 6) when the184th Infantry met well entrenched Imperial forces in fortified positions at the Pinnacle (one of the first battle sites on Okinawa). Days later, on L+18 (April 19), the 7th discovered more Imperial forces at Skyline Ridge.
What was coming next no intelligence unit could have predicted. With the Army divisions moving southward and Marine divisions moving northward, neither of them knew it at the time but they were both about to be stopped in their tracks and discover where the real, concentrated resistance of the Imperial forces lay. Each escarpment, each hill became a battlefield of its own, all supported by the neighboring escarpments and hills. Artillery and mortars reigned down from reverse slope firing points with pinpoint accuracy. Snipers fired from cave and tombs openings, and everywhere the Army went they encountered Japanese civilians who they did not know if they were friend or foe. The 7th, who kicked off the ground fighting against Imperial forces at the Battle of Attu, were now on Okinawa working to end the fighting.
And the worst of the fighting was yet to come.
Invasion of Okinawa Fast Facts:
1.) The initial invasion force for Okinawa was roughly 183,000 Soldiers, Marines, Sailors, and Guardsmen. This is 30,000 more than the D-Day invasion.
2.) The invasion fleet was comprised of over 2,500 battleships, aircraft carriers, destroyers, and landing craft.
3.) Okinawa was divided in two at the Bishigawa River (now the Hija River), the Marines went north while the Army went south.
4.) The invasion began so unopposed that Soldiers and Marines resorted to walking ashore upright, not worried about being engaged by the enemy.
5.) The American shelling and bombardment of Okinawa was observed by the top three Japanese commanding officers of the 32nd Imperial Army, General Mitsuru Ushijimya, Lieutenant General Isamu Cho, and Colonel Hiromichi Yahara, of the Imperial forces on Okinawa. from Shuri Jo (the castle that the 32nd Army was using as a headquarters), supposedly COL Yahara (chief planning officer for the 32nd) remarked “What a waste.”
6.) The invasion was a complete success and went unopposed for the four days preceding the battle at Cactus Ridge where the first elements of the Imperial forces engaged the American forces. Cactus Ridge is located on present day Marine Airbase Futenma.
Evan Muxen is the Historian for the 446th Airlift Wing, ARFC, located at Joint Base Lewis-McChord. He previously served as the Command Historian for the 18th Wing at Kadena Airbase in Okinawa, Japan, the U.S. Air Force's largest combat wing.