Which war in 2001 is subjectively deemed a world war?
World war 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).
Two-front war In military terminology, a two-front war is a war in which fighting takes place on two geographically separate fronts. It is usually executed by two or more separate forces simultaneously or nearly simultaneously, in the hope that their opponent will be forced to split their fighting force to deal with both threats, therefore reducing their odds of success. Where one of the contending forces is surrounded, the fronts are called interior lines.