In this there have been several such wars in world history. The first and second world war get max attention since they involved conflict in several locations throughout the world. But before theses wars was the napoleonic wars that stretched from Europe to the Middle-east and India, and even America given when Napoleon captured the king of Spain he set off multiple revolutions and conflicts within the Spanish Empire. Above all Napoleon's destruction of the Knights of Malta set loose islamic piracy throughout the Med that eventually forced America into the first and second Barbary wars.
Thus, to limit the idea of a World War to the now obsolete idea of a major nuclear exchange between the United States and say Russia is incorrect. In the same regard to limit it to the concept of event major conventional war with heavy artillery, bombers and large formations of troops is also incorrect. These points were made recently in a Huff post piece which I feel should be read by many.
This new war is being waged with small units, light arms and a form of blitzkrieg that would make Hitler take notice. And we have not seen since the Kamikaze attacks on our ships in the Pacific the kind of martyrdom philosophy waged now. In point, the kamikaze is today either ignored by modern writers or completely corrupted to suggest something else just so it can be explained to western european people.