Japanese counter-attacks once the islands were secure. However, General Douglas MacArthur strenuously objected to any plan that would delay his return to the Philippines. His objections were routed through formal channels as well as bypassing the Joint Chiefs of Staff, appealing directly to Secretary of War Henry Stimson and President Franklin D. Roosevelt. MacArthur's objections were not without tactical reasoning based on the experience of the invasion of Tarawa (Operation Galvanic), but were voiced before the vastly improved experience in the Gilbert and Marshall Islands (Operation Flintlock - Kwajalein, Eniwetok and other islands/atolls), the increase in naval forces, the successful attack on Truk and the Carolines islands by carrier-based aircraft (Hailstone), and coordinated armed services experience gained by all these operations in Admiral Chester Nimitz’s Pacific Ocean Area of operations. While not part of the original American plan, MacArthur, commander of the Southwest Pacific Area command, obtained authorization to advance through New Guinea and Morotai toward the Philippines. This allowed MacArthur to keep his personal pledge to liberate the Philippines, made in his "I shall return" speech, and also allowed the active use of the large forces built up in the southwest Pacific theatre. The Japanese, expecting an attack somewhere on their perimeter, thought an attack on the Caroline Islands most likely. To reinforce and supply their garrisons, they needed naval and air superiority, so Operation A-Go, a major carrier attack, was prepared for June 1944. Opposing forces United States US Fifth Fleet Admiral Raymond A. Spruance Northern Attack Force (Task Force 52) Vice Admiral Richmond Kelly Turner Expeditionary Troops (Task Force 56) Lieut. General Holland M. Smith, USMC Approx. 59,800 officers and enlisted V Amphibious Corps (Lt. Gen. Smith) 2nd Marine Division (Maj. Gen. Thomas E. Watson, USMC) 4th Marine Division (Maj. Gen. Harry Schmidt, USMC) 27th Infantry Division (Army) (Maj. Gen. Ralph C. Smith, USA) Japan Central Pacific Area Fleet HQ Vice Admiral Chūichi Nagumo Thirty-first Army Lieut. General Hideyoshi Obata Defenses of Saipan Lieut. General Yoshitsugu Saitō Approx. 25,500 army and 6,200 navy personnel 43rd Division 47th Independent Mixed Brigade Miscellaneous units Battle The bombardment of Saipan began on 13 June 1944 with seven modern fast battleships, 11 destroyers and 10 fast minesweepers under Vice Admiral Willis A. Lee Jr. The battleships delivered 2,400 shells, but to avoid potential minefields, fire was from a distance of or more and crews were inexperienced in shore bombardment. The following