The only significant local military event during the war was a 1915 mutiny by the British Muslim Indian sepoys garrisoned in Singapore. After hearing rumors of plans to send them to fight the Ottoman Empire, the soldiers revolted, killing their officers and several British civilians before troops arriving from Johor and Burma suppressed the unrest. After the war, the British government devoted significant resources into building a naval base in Singapore, as a deterrent to the increasingly ambitious Japanese Empire. Completed in 1939 at a staggering cost of $500 million, the naval base boasted what was then the largest dry dock in the world, the third-largest floating dock, and enough fuel tanks to support the entire British navy for six months. It was defended by heavy 15-inch naval guns and by Royal Air Force squadrons stationed at Tengah Air Base. Winston Churchill touted it as the "Gibraltar of the East." Unfortunately, it was a base without a fleet. The British Home Fleet was stationed in Europe and the plan was for it to sail quickly to Singapore when needed. However, after World War II broke out in 1939, the Fleet was fully occupied with defending Britain. Lieutenant General Sir William George Shedden Dobbie was appointed governor of Singapore and General Officer Commanding Malaya Command on 8 November 1935, holding the post based in The Istana until shortly before the outbreak of World War II in 1939. He was responsible for forming The Dobbie Hypothesis on the fall of Singapore which, had it been heeded, may have prevented the fall of Singapore during the Second World War. In December 1941, Japan attacked Pearl Harbor and the east coast of Malaya, causing the Pacific War to begin in earnest. Both attacks occurred at the same time, but due to the international dateline, the Honolulu attack is dated 7 December while the Kota Bharu attack is dated 8 December. One of Japan's objectives was to capture Southeast Asia and secure the rich supply of natural resources to feed its military and industry needs. Singapore, the main Allied base in the region, was an obvious military target because of its flourishing trade and wealth. The British military commanders in Singapore had believed that the Japanese attack would come by sea from the south since the dense Malayan jungle in the north would serve as a natural barrier against invasion. Although they had drawn up a plan for dealing with an attack on northern Malaya, preparations were never completed. The military was confident that "Fortress Singapore" would withstand any Japanese attack and this confidence was further reinforced by the arrival of Force Z, a squadron of British warships dispatched to the defense of Singapore, including the battleship , and cruiser .