The '2nd Raid on Kure' was undertaken by US and British naval forces against Japan’s Combined Fleet, which lost most of its surviving major warship strength (24/28 July 1945).
The attacks of Task Force 38 of Admiral William F. Halsey’s 3rd Fleet on Kure Naval Arsenal and nearby ports on 24, 25, and 28 July sank one fleet carrier, three battleships, five cruisers and several smaller warships. During the same period Task Force 37 of the British Pacific Fleet, under the local command of Vice Admiral Sir Bernard Rawlings, attacked other targets in the Inland Sea region and sank two escort ships and several smaller vessels as well as damaging an escort carrier.
In July 1945 the Imperial Japanese navy’s remaining large warships of Vice Admiral Kanazawa Masao’s Combined Fleet were concentrated near the major naval base of Kure on the Inland Sea. The ships were immobilised by fuel shortages and were being used only as stationary anti-aircraft batteries. Admiral John S. McCain, commander of the Fast Carrier Task Force, strongly opposed attacking Kure as he and his staff believed that the ships posed only a minor threat. In his memoirs, Halsey gave four reasons for why he attacked Kure despite McCain’s objections: firstly, he believed that the attack would boost US morale and retaliate for the Japanese 'Ai' carrierborne air attack on Pearl Harbor in December 1941; secondly, it would ensure that the Japanese could not disrupt the planned Soviet invasion of Hokkaido, northernmost of the Japanese home islands; thirdly, it would prevent Japan from using its fleet as a bargaining point to secure better peace terms; and fourthly, he had been ordered to undertake the attack by Fleet Admiral Chester W. Nimitz, commander-in-chief of the Pacific Fleet.
Despite operating as Task Group 37 of the US 3rd Fleet, the British Pacific Fleet was excluded from the attack on Kure because the Americans did not want Britain to claim a part in destroying the Japanese fleet. The British strength was instead used to attack airfields and the port of Osaka.
Kure had been subjected to several major attacks before July 1945. On 19 March 1945, 321 US Navy aircraft attacked Japanese warships in and around the city. This '1st Raid on Kure' attack was unsuccessful, no Japanese ships being sunk although an escort carrier and a light cruiser were badly damaged. On 5 May Boeing B-29 Superfortress four-engined heavy bombers of the US 20th Army Air Force successfully bombed the Hiro naval aircraft factory. B-29 bombers laid naval mines in the approaches to the port on 30 March and 5 May, and 40% of the city was destroyed in a major air raid conducted by B-29 bombers on 1 July.
The 3rd Fleet’s attack on Kure began on 24 July, a day on which US carrierborne aircraft flew 1,747 sorties against Japanese targets. The attacks sank the aircraft carrier Amagi and the light cruiser Oyodo, which was acting as the Combined Fleet's flagship. The hybrid battleship/carriers Hyuga and Ise, the battleship Haruna, the heavy cruisers Tone and Aoba, and the obsolete armoured training cruisers Iwate and Izumo were all heavily damaged and settled in shallow water. The shallow water of the anchorage precluded the US use of torpedoes. The US aircraft attempted to reduce their losses from the large number of anti-aircraft guns in the area by the use of variable time-fused bombs.
The British Pacific Fleet’s attacks against Osaka and targets in the Inland Sea damaged the escort carrier Kaiyo and sank the escort ships No. 4 and No. 30 for the loss of four aircraft.
US attacks on Kure resumed on 28 July, further damaging Ise, Haruna and Aoba. The aircraft carrier Katsuragi, which had largely escaped attack in the earlier raid, and the unserviceable light aircraft carrier Ryuho were attacked, and Katsuragi sustained heavy damage. These air attacks were among the largest conducted by the US Navy during the war, and were the most destructive of shipping.
On 28 July, the USAAF attacked the ships at Kure with 79 Consolidated B-24 Liberator four-engined heavy bombers operating from the captured island of Okinawa. Four hits were made on the beached Aoba, breaking off her stern, and two B-24 bombers were shot down and 14 others damaged.
Allied losses included 102 aircrew and 133 aircraft lost in combat or accidents during the attacks. These losses were higher than those suffered by the 3rd Fleet in most of its operations, and resulted largely from the heavy anti-aircraft defences around Kure.
The Allied attacks on Kure and the Inland Sea left Nagato at Yokosuka as the only remaining capital ship in Japan’s naval inventory, and the attacks allowed the Soviet Pacific Fleet to operate in the Sea of Japan without fear of coming under attack by Japanese ships.