Quick questions on The Pacific war and the fall of Singapore explained: N(A)-Level History

Before the war, Singapore was a key British naval base in Asia and was widely believed to be almost impossible to capture. The British had built powerful defences, and many people, both in Britain and in the region, were confident that Singapore could hold out against any enemy. This confidence turned out to be dangerously misplaced. The defences were designed mainly to stop an attack coming by sea, with big guns pointing out to the ocean.

When Japan entered the war, it launched a swift attack on British territory in the region. Rather than attacking Singapore directly from the sea, the Japanese landed in the north and advanced down the Malay Peninsula toward Singapore by land, from exactly the direction the British had thought unlikely. The Japanese moved with surprising speed, pushing through difficult country, sometimes using bicycles to advance quickly along the roads. They had strong support from aircraft and had sunk major British warships, leaving the British without the sea and air power they needed.

The British defence had several serious weaknesses. They were short of modern aircraft and had few tanks, while the Japanese had both. British and Allied forces were poorly coordinated and their commanders had badly underestimated the Japanese, wrongly assuming they were not a first-class fighting force. As the Japanese advanced, British morale fell.

In February 1942 the British commander surrendered Singapore to the Japanese. Huge numbers of British and Allied troops were taken prisoner in what was one of the largest surrenders in British military history. The fall of the "impregnable fortress" stunned the world. For the people of Singapore, it meant the beginning of a harsh period of Japanese occupation that would last until the end of the war.

Explain the reasons for the defeat, defences facing the wrong way, British weaknesses, Japanese skill, rather than just describing the battle.