Answer: WWI

AnswerCrossword Clue
WWISetting for Sgt. York's heroics
WWITeens conflict, briefly
WWIConflict for the A.E.F.
WWI"Gallipoli" conflict, briefly
WWI"All Quiet on the Western Front" conflict (abbr.)
WWIBattle of the Somme setting, for short
WWI"A Farewell to Arms" setting, briefly
WWIIt ended at 11:00 on 11-11-18
WWIIt ended on Nov. 11
WWIIt was over on 11-11 at 11 a.m.
WWIRed Baron's conflict, briefly
WWIConflict that ended Nov. 11, 1918
WWIIt ended in '18
WWIIt began 7-28-1914
WWIDoughboy's conflict, briefly
WWIDoughboys' conflict: Abbr.
WWIAEF conflict
WWI1914-18 conflict, for short
WWI20th cen. conflict
WWIDoughboys' conflict, for short
WWILa Belle Epoque ender: Abbr.
WWI"A Farewell to Arms" backdrop, for short
WWIThe "Big One"
WWI"All Quiet on the Western Front" conflict
WWITheater of 1914-1918: Abbr.
WWIDoughboys' conflict (abbr.)
WWIRed Baron's conflict, for short
WWIGlobal conflict
WWI1914-18 event
WWI"Over There" occasion, for short
WWIIt ended on 11-11
WWIBig Bertha's milieu
WWIIt ended Nov. 11th
WWIBig conflict of the 1910s, briefly
WWIIt marked the beginning of the "Lost Generation"
WWIThe Ottoman Emp. fell shortly after it
WWIIt ended Nov. 11, 1918
WWITeens conflict: Abbr.
WWI"A Farewell to Arms" conflict, briefly
WWIFour-yr. conflict