World war
A world war was a war fought by all or most of a world's dominant nations.

Humans fought three world wars on Earth and were almost destroyed. Whole generations were nearly wiped out. ()

In 2267, Lieutenant Commander Spock – speaking to Terran crewmembers – referred to the mid-1990s as the era of their last so-called world war, to which Doctor Leonard McCoy responded the Eugenics Wars. ()

In a Dixon Hill holoprogram set before the United States' involvement in Earth's Second World War, Rex noted that Germany was getting ready to invade England. In regard to who would stop Germany,  responded that the last thing the United States needed to do was fight in another world war. ()

List of world wars 
World War I
World War II
World War II (Temporal War)
World War III

External link
 

Conflicts