<Tr> <Td> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> </Td> </Tr> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> <P> A world war, as it is commonly understood, is a large - scale war involving many of the countries of the world or many of the most powerful and populous ones . World wars span multiple countries on multiple continents, with battles fought in many theaters . While a variety of global conflicts have been subjectively deemed "world wars", such as the Cold War and the War on Terror, the term is widely and generally accepted only as it is retrospectively applied to two major international conflicts that occurred during the 20th century: World War I (1914--1918) and World War II (1939--1945). </P> <P> The Oxford English Dictionary cited the first known usage in the English language to a Scottish newspaper: the People's Journal in 1848: "A war among the great powers is now necessarily a world - war ." The term "world war" had been used in 1850 by Karl Marx and his associate, Friedrich Engels, in The Class Struggles in France . Rasmus B. Anderson in 1889 described an episode in Teutonic mythology as a "world war" (Swedish: världskrig), justifying this description by a line in an Old Norse epic poem, "Völuspá: folcvig fyrst i heimi" ("The first great war in the world".) German writer August Wilhelm Otto Niemann had used the term "world war" in the title of his anti-British novel, Der Weltkrieg: Deutsche Träume (The World War: German Dreams) in 1904, published in English as The Coming Conquest of England . </P>

When did world war 2 become a world war