Second World War; World War II; WWII
Historical term for the global conflict from 1939 to 1945. Often used in formal or educational contexts.
World War II began in 1939.
He wrote a book about World War II.
Many cities were bombed during World War II.
World War II ended in 1945.
After World War II, Japan recovered rapidly.
太平洋戦争 specifically denotes the Pacific theater (1941–1945) involving Japan and the US, whereas 第二次世界大戦 covers the entire global conflict including the European front.