With the onset of World War 2 in Europe, many of the Allies were busy fighting German forces and the Axis powers, with little or no focus on the Pacific Ocean. This was a strategic loophole Japan could exploit. It assumed that the situation was conducive to achieving its objectives as the Pacific theater was virtually off everybody’s sights for the war in Europe. This would give Japan the covert advantage for invading territory which was virtually left unguarded. However, the US had long sensed Japanese military designs over the region around the Pacific and had concentrated on building up its presence through its naval fleet in the Philippines, hoping to deter Japan. It was also a move designed to protect the US’s own commercial, not military interests in the region.
On December 7th, the Japanese naval fleet attacked Pearl Harbor which was a naval base for the US navy. By doing so, the Japanese military government hoped to bring America to its knees and force it to accept a negotiated settlement enabling it to gain undiluted control over the region. But it misread the situation which bloomed into a full scale conflict with America entering World War 2 after Pearl Harbor. The Japanese defeated in the battle of Midway, were forced to surrender to America. However, the full terms of the surrender came into operation a year later because sporadic resistance in parts of the Japanese colonies prolonged resistance.