<P> Japan planned to rapidly seize European colonies in Asia to create a large defensive perimeter stretching into the Central Pacific; the Japanese would then be free to exploit the resources of Southeast Asia while exhausting the over-stretched Allies by fighting a defensive war . To prevent American intervention while securing the perimeter it was further planned to neutralise the United States Pacific Fleet and the American military presence in the Philippines from the outset . On 7 December 1941 (8 December in Asian time zones), Japan attacked British and American holdings with near - simultaneous offensives against Southeast Asia and the Central Pacific . These included an attack on the American fleet at Pearl Harbor, the Philippines, landings in Thailand and Malaya and the battle of Hong Kong . </P> <P> These attacks led the United States, Britain, China, Australia and several other states to formally declare war on Japan, whereas the Soviet Union, being heavily involved in large - scale hostilities with European Axis countries, maintained its neutrality agreement with Japan . Germany, followed by the other Axis states, declared war on the United States in solidarity with Japan, citing as justification the American attacks on German war vessels that had been ordered by Roosevelt . </P> <P> On 1 January 1942, the Allied Big Four--the Soviet Union, China, Britain and the United States--and 22 smaller or exiled governments issued the Declaration by United Nations, thereby affirming the Atlantic Charter, and agreeing to not to sign a separate peace with the Axis powers . </P> <P> During 1942, Allied officials debated on the appropriate grand strategy to pursue . All agreed that defeating Germany was the primary objective . The Americans favoured a straightforward, large - scale attack on Germany through France . The Soviets were also demanding a second front . The British, on the other hand, argued that military operations should target peripheral areas to wear out German strength, leading to increasing demoralisation, and bolster resistance forces . Germany itself would be subject to a heavy bombing campaign . An offensive against Germany would then be launched primarily by Allied armour without using large - scale armies . Eventually, the British persuaded the Americans that a landing in France was infeasible in 1942 and they should instead focus on driving the Axis out of North Africa . </P>

Where did germany begin its offensive and what happened there