British strategy in the Far East centred on the dispatch of a balanced fleet to Singapore. The Army's role was essentially an Imperial garrison. Unfortunately, financial pressures in the 1930s had delayed the completion of Singapore as a major naval base with full ship repair facilities.
At the start of hostilities in Europe, matters deteriorated particularly for the Royal Navy in the Atlantic, home waters and Mediterranean. An economically constrained rearmament program meant the Royal Navy now faced a crippling lack of modern warships for the Far East. Japan took advantage of the collapse of France to occupy southern French Indo-China during the summer of 1941. The demands of war in the European and the Mediterranean theatres were stretching Britain's ability to defend on a global scale to breaking point.
The first Japanese assaults followed the Imperial Japanese Navy's surprise attack on the American Pacific Fleet at Pearl Harbour. On 8 December the Japanese army crossed into the New Territories of Hong Kong, and by 12 December British and Imperial troops had been forced back onto Hong Kong Island, which the Japanese assaulted six days later. By Christmas Day, it was clear that further resistance was impossible, and what was left of the garrison surrendered.
The British and Imperial performance in Malaya was perhaps the worst of the war. The army, civilians and government were psychologically unready to resist the Japanese.
The Japanese plan was simple and was anticipated by the British (Malaya was easily defended from all invasion routes except sea). The Japanese main force advanced along two parallel routes down the west coast of Malaya, using the main truck road of the peninsula. At the same time, another smaller force was to land at Khota Bharu in the far North East of Malaya, with the aim of capturing airfields in that region. The plan was constrained by the terrain of Malaya, and the British had no problem in disposing troops to meet it. However, the British response immediately met with disaster at sea with the destruction of Force Z (the new battleship HMS Prince of Wales and the battle cruiser HMS Repulse) by land-based Japanese naval aircraft. As a result, there was no way of stopping the seaborne invasion force.
The British troops meeting the Japanese invasion forces were, on the whole, poorly trained, poorly led and poorly equipped. The Japanese, using minimal forces and completely orthodox tactics, managed to manoeuvre the British forces out of one position after another. The British high command in Malaya had failed to grip the battle. As a result, despite Allied units inflicting sometimes heavy losses on the Japanese, morale and fighting efficiency started to crumble.
Soon the British were forced back on to Singapore Island, where the civil authorities were totally unprepared for either a Japanese assault or a siege of any description. With no fleet to base in Singapore, and no aircraft to defend it, efforts were made to demolish the new naval base before the Japanese captured it.