On 1 September 1939, Germany invaded Poland. It was the start of a conflict that would erupt over every continent, see the deaths of tens of millions of people, much of central Europe destroyed, the development of jets, ballistic missiles and computers as well as the atomic bomb.
The year 1942 saw the eruption of war in the Far East as Japanese forces continued the offensive across Asia and the Pacific, which had begun with the attacks on Pearl Harbor in December 1941. However, the Japanese advance would be checked at the Battle of the Coral Sea, Guadalcanal and, most importantly, the Battle of Midway. Meanwhile, the US was building up its strength in Europe as well, the Eighth Air Force beginning offensive operations against Germany, while fighting continued in the Mediterranean and North Africa as the Malta convoys continued to scrape through and the Battle of Stalingrad dominated the Eastern Front. The Second World War was now a truly global conflict.