Answer: ETO
ETO is a crossword puzzle answer that we have spotted 186 times.
    - D.D.E.'s command
 
    - W.W. II command
 
    - 1944 initials
 
    - W.W. II arena
 
    - W.W. II arena: Abbr.
 
    - Montgomery's field: Abbr.
 
    - W.W. II zone
 
    - W.W. II field
 
    - Command for D.D.E.
 
    - Ike's W.W. II command
 
    - Ike's command: Abbr.
 
    - D.D.E.'s command in W.W. II
 
    - Pacific's counterpart in W.W. II: Abbr.
 
    - Mil. arena abroad
 
    - Verdun was in it once: Abbr.
 
    - Area of 1940's mil. activity
 
    - W.W. II inits.
 
    - D.D.E.'s arena
 
    - W.W. II action locale
 
    - D.D.E.'s oversight, once
 
    - Axis/Allies war zone: Abbr.
 
    - Part of a W.W. II mil. map
 
    - W.W. II combat area: Abbr.
 
    - War zone, in brief
 
    - D.D.E.'s command, once
 
    - St. Lô was in it in W.W. II
 
    - Ike's command, once: Abbr.
 
    - W.W. II area: Abbr.
 
    - D.D.E.'s W.W. II command
 
    - 40's arena, for short
 
    - W.W. II region: Abbr.
 
    - 1940's arena: Abbr.
 
    - Ike's command in W.W. II
 
    - W.W. II map: Abbr.
 
    - W.W. II area
 
    - W.W. II sphere: Abbr.
 
    - Overlord's area: Abbr.
 
    - W.W. II command: Abbr.
 
    - Old war zone: Abbr.
 
    - W.W. II war zone: Abbr.
 
    - D.D.E.'s purview
 
    - On a par with
 
    - Ike's W.W. II command, for short
 
    - The Rhineland Campaign was part of it: Abbr.
 
    - D.D.E.'s purview in W.W. II
 
    - D-Day arena: Abbr.
 
    - Abbr. on W.W. II maps
 
    - Ike's W.W. II domain
 
    - Historical war zone: Abbr.
 
    - Ike's W.W. II arena
 
    - D.D.E. zone
 
    - Arena where 37-Downs were used: Abbr.
 
    - DDE's command
 
    - Command for DDE
 
    - DDE's arena
 
    - WWII area
 
    - WWII command
 
    - WWII arena
 
    - DDE's WWII command
 
    - Ike's WWII command
 
    - Eisenhower's WWII command
 
    - DDE's WWII bailiwick
 
    - DDE's zone
 
    - WWII movie setting
 
    - WWII zone
 
    - Ike's one-time purview
 
    - WWII battle zone
 
    - Ike's WWII turf
 
    - DDE's 1942 command
 
    - DDE's bailiwick
 
    - Ike's WWII responsibility
 
    - DDE's 1940s command
 
    - Ike's World War II command
 
    - 1940s arena, briefly
 
    - Ike commanded it
 
    - DDE's command, once
 
    - D.D.E.'s command in WWII
 
    - WWII abbr.
 
    - W.W. II command area
 
    - D.D.E.'s 1942 command
 
    - Ike's command
 
    - Area commanded by DDE
 
    - The Normandy Campaign was part of it: Abbr.
 
    - Site of 1940s military ops
 
    - Battle of the Bulge arena: Abbr.
 
    - Gen. Eisenhower commanded it
 
    - DDE's command in WWII
 
    - Kilroy was there: Abbr.
 
    - Arena for DDE
 
    - Ike's arena: Abbr.
 
    - DDE command
 
    - 1940s overseas cmd.
 
    - Cmd. established 6/8/1942
 
    - Ike's 1940s turf
 
    - Ike's arena, briefly
 
    - Lt. Gen. Devers commanded it before DDE
 
    - DDE arena
 
    - Zone for DDE
 
    - 1940s command, briefly
 
    - Ike's WWII sphere
 
    - DDE bailiwick
 
    - 14 Down bailiwick
 
    - Region led by DDE
 
    - Ike's turf, once
 
    - D.D.E.'s WWII command
 
    - Zone for D.D.E.
 
    - Area commanded by D.D.E.
 
    - Ike's WWII domain
 
    - WWII milit. command
 
    - WWII command for D.D.E.
 
    - WWII combat area, briefly
 
    - Ike's command in WWII
 
    - Domain of the Normandy campaign: Abbr.
 
    - Ike's arena
 
    - W.W. II zone: Abbr.
 
    - Ike's WWII arena
 
    - 1-Down's W.W. II command
 
    - '40s arena, briefly
 
    - 1940s mil. venue
 
    - Onetime D.D.E. command
 
    - WWII action locale
 
    - DDE's wartime arena
 
    - 1940s theater, for short
 
    - WWII arena: abbr.
 
    - Gen. Eisenhower's command
 
    - WWII sphere
 
    - DDE's WW2 bailiwick
 
    - WWII theater
 
    - Normandy was in it: Abbr.
 
    - The Lorraine Campaign was part of it: Abbr.
 
    - It once stretched from France to Russia: Abbr.
 
    - Army formation of WWII
 
    - Where the 34th Infantry Division fought: Abbr.
 
    - WWII area: abbr.
 
    - DDE's responsibility
 
    - Ike's old command
 
    - Allies' arena: Abbr.
 
    - Gen. Bradley's area: Abbr.
 
    - Gen. Eisenhower's arena: Abbr.
 
    - Ike's domain in WWII
 
    - DDE milieu
 
    - W.W. II command area: Abbr.
 
    - 1940s arena: Abbr.
 
    - Eisenhower's command, for short
 
    - Rhineland Campaign's arena: Abbr.
 
    - WWII venue
 
    - Ike's WWII baillwick
 
    - WWII region
 
    - Gen. Eisenhower's WWII command
 
    - DDE's WWII arena
 
    - 1940s command: Abbr.
 
    - 1940s mil. zone
 
    - WWII zone: Abbr.
 
    - Maginot Line arena: abbr.
 
    - Ike's 1940s command
 
    - WWII mil. zone
 
    - WWII domain
 
    - W.W. II domain: Abbr.
 
    - Ike's theater
 
    - Eisenhower's WWII purview
 
    - DDE's military arena
 
    - Ike's charge during W.W. II
 
    - Ike's wartime command
 
    - D.D.E.'s charge in W.W. II
 
    - 1940s stage for Ike
 
    - WW II scene of operations
 
    - Where many saw action in the '40s
 
    - Large W.W. II area: Abbr.
 
    - W.W. II zone, for short
 
    - DDE's overseas command
 
    - DDE's WWII sphere
 
    - Ike's charge in W.W. II
 
    - Ike and Monty's bailiwick
 
    - DDE's wartime command
 
    - Ike's battleground
 
    - DDE's domain
 
    - Abbr. in "secrets of world war ii"
 
    - Ike's command in 21-Across
 
    - W.W. II zone that D.D.E. commanded
 
    - DDE's WWII domain
 
    - Ike's W.W. II command: Abbr.
 
    - 1940s combat zone, in brief
 
    - Ike's domain in W.W. II
 
    - WWII command for 16-Across
 
    - W.W. II war zone, in brief
 
    - D.D.E.'s W.W. II battleground