when did the us enter japan in ww2
Pacific War The Second Sino-Japanese War between the Empire of Japan and the Republic of China had been in progress since 7 July 1937, with hostilities dating back as far as 19 September 1931 with the Japanese invasion of Manchuria.[43] However, it is more widely accepted[nb 9][45] that the Pacific War itself began on 7/8 December 1941, when Japan invaded Thailand and attacked the British possessions of Malaya, Singapore, and Hong Kong as well as the United States military and naval bases in Hawaii, Wake Island, Guam and the Philippines.[46][47][48]
World War II The start of the war in Europe is generally held to be 1 September 1939,[9][10] beginning with the German invasion of Poland; Britain and France declared war on Germany two days later. The dates for the beginning of war in the Pacific include the start of the Second Sino-Japanese War on 7 July 1937,[11][12] or even the Japanese invasion of Manchuria on 19 September 1931.[13][14]
Korean War After the first two months of war, South Korean and U.S. forces rapidly dispatched to Korea were on the point of defeat, forced back to a small area in the south known as the Pusan Perimeter. In September 1950, an amphibious UN counter-offensive was launched at Incheon, and cut off many North Korean troops. Those who escaped envelopment and capture were forced back north. UN forces rapidly approached the Yalu River—the border with China—but in October 1950, mass Chinese forces crossed the Yalu and entered the war.[45] The surprise Chinese intervention triggered a retreat of UN forces which continued until mid-1951.
American entry into World War I In 1917, with Russia experiencing political upheaval following widespread disillusionment there over the war, and with Britain and France low on credit, Germany appeared to have the upper hand in Europe,[3] while Germany's ally, the Ottoman Empire, clung stubbornly to its possessions in the Middle East. In the same year, Germany decided to resume unrestricted submarine warfare against any vessel approaching British waters; this attempt to starve Britain into surrender was balanced against the knowledge that it would almost certainly bring the United States into the war. Germany also made a secret offer to help Mexico regain territories lost in the Mexican–American War in an encoded telegram known as the Zimmermann Telegram, which was intercepted by British Intelligence. Publication of that communique outraged Americans just as German U-boats started sinking American merchant ships in the North Atlantic. Wilson then asked Congress for "a war to end all wars" that would "make the world safe for democracy", and Congress voted to declare war on Germany on April 6, 1917.[4]