War Nick

Teutonic migration known as the Great War, in The Great Gatsby?

What is this event, actually? When Nick mentions this, does this mean he actually fought in a ‘Great War’ or is this a metaphor for something else?
Thanks!

He means the Great War, or World War I. Nick is being ironic, comparing a horrifying war to an innocent “delayed Teutonic migration.” Nick has fought in World War I, but part of being a graceful man is being modest about one’s activities, especially as a soldier. This light way of referring to his experiences is to Nick’s credit, since he claims no heroism, whatever he may have done in the war itself. Gatsby is similarly modest about his wartime exploits, when he meets Nick in Chapter IV.

Puppet Theatre/War Of The Roses “Stoner Nick”