The Strategic Importance of the Marianas

In June 1944, the Pacific War reached a critical turning point as American forces set their sights on the Mariana Islands. Known to the Japanese as the “Pacific Breakwater,” this island chain served as a crucial defensive barrier protecting Japan’s southern flank. For the U.S., capturing the Marianas—particularly Saipan, Tinian, and Guam—would provide vital forward bases for launching attacks on the Philippines or even the Japanese mainland.

Admiral Chester Nimitz, commander of the U.S. Pacific Fleet, chose June 6, 1944, as the launch date for the invasion—coinciding with the D-Day landings in Normandy. While Allied forces stormed the beaches of France, the U.S. 5th Fleet, led by Admiral Raymond Spruance, departed the Marshall Islands, bound for the Marianas. The invasion force was massive: 535 ships carrying over 127,000 Marines and soldiers.

The Opening Moves: American Air Superiority

On June 11, 1944, Task Force 58, under Vice Admiral Marc Mitscher, launched a devastating air assault on Japanese airfields in the Marianas. The attack caught the Japanese by surprise—most of their aircraft had been diverted to reinforce New Guinea, leaving their defenses weakened. Over 100 Japanese planes were destroyed, and critical infrastructure was heavily damaged. By June 15, American forces had secured air superiority, paving the way for the amphibious assault on Saipan.

The Japanese response was swift. Admiral Soemu Toyoda, commander of the Combined Fleet, ordered Operation A-Go, a decisive naval counterattack. Vice Admiral Jisaburō Ozawa’s Mobile Fleet, including nine aircraft carriers, sortied from the Philippines, hoping to replicate Japan’s early-war successes. However, by 1944, American submarine and aerial reconnaissance had vastly improved, allowing Spruance to track Ozawa’s movements.

The “Great Marianas Turkey Shoot”

On June 19, 1944, the Battle of the Philippine Sea erupted in what would become one of the most lopsided air battles in history. Ozawa launched four massive airstrikes against the U.S. fleet, but American radar and fighter coordination proved devastating. U.S. pilots, flying F6F Hellcats, intercepted the poorly trained Japanese aviators with ruthless efficiency.

The first wave of 64 Japanese aircraft was met by over 450 Hellcats. In what American pilots later called the “Great Marianas Turkey Shoot,” only 26 Japanese planes returned. Subsequent waves fared even worse. By day’s end, Japan had lost over 350 aircraft, while U.S. losses were minimal. Worse for the Japanese, American submarines USS Albacore and USS Cavalla torpedoed and sank two of Ozawa’s finest carriers—Taihō and Shōkaku.

The American Counterattack

With Japanese airpower crippled, Spruance ordered a daring dusk strike on June 20. Despite the risks of nighttime carrier operations, 216 American aircraft pursued Ozawa’s retreating fleet. They found and heavily damaged three more carriers (Hiyō, Jun’yō, and Chiyoda) and sank the carrier Hiyō. However, the return flight proved harrowing—many planes ran out of fuel, forcing emergency landings. In a bold decision, Mitscher ordered all ships to illuminate their decks, saving countless pilots but exposing the fleet to potential submarine attacks.

Aftermath and Legacy

The Battle of the Philippine Sea was a catastrophic defeat for Japan. Three carriers were sunk, and over 90% of Ozawa’s aircraft were destroyed. The loss of experienced pilots and ships left the Imperial Japanese Navy unable to mount another major carrier offensive. For the U.S., the victory secured the Marianas, enabling the bombing campaign against Japan and the eventual liberation of the Philippines.

Historians debate whether Spruance missed an opportunity to annihilate Ozawa’s fleet entirely, but the battle’s outcome was undeniable: American naval dominance in the Pacific was now absolute. The “Turkey Shoot” not only shattered Japan’s naval airpower but also marked the beginning of the end for Imperial Japan’s Pacific ambitions.