Question: Lorraine Campaign and Operation Undertone both occurred during which war?

Context paragraphs:
Operation Undertone: Operation Undertone was a large assault by the U.S. Seventh and French 1st Armies of the U.S. Sixth Army Group as part of the Allied invasion of Germany in March 1945 during World War II.

VI Corps (United States): The VI Corps was activated as VI Army Corps in August 1918 at Neufchâteau, France, serving in the Lorraine Campaign.  Constituted in the Organized Reserves in 1921, it was allotted to the Regular Army in 1933 and activated on 1 August 1940 at Fort Sheridan, Illinois.  VI Corps took part in some of the most high-profile operations in World War II.

Ouvrage Schiesseck: Ouvrage Schiesseck is a "gros ouvrage" of the Maginot Line, located near Bitche in the French "département" of Moselle.  Schiesseck is adjoined by "gros ouvrage" Simserhof and "petit ouvrage" Otterbiel, all part of the Fortified Sector of Rohrbach, and faces the German frontier.  Schiesseck saw comparatively little activity during the Battle of France, surrendering with other positions in its sector on 30 June 1940.  During the Lorraine Campaign of 1944 Schiesseck was occupied by German forces and presented a point of resistance to American advances, requiring heavy bombardment and infantry assaults by engineer units to capture.  The area was abandoned during the Battle of the Bulge, but was recaptured in March 1945.  In the 1950s Schiesseck was repaired as part of a program to re-arm the Maginot Line against a potential advance by Warsaw Pact forces.  It was abandoned in the early 1970s.  Schiesseck is on military land and is not visitable by the public.

Lorraine Campaign order of battle: The following units and commanders participated in the Lorraine Campaign from September 1 to December 1, 1944.

Hugh M. Cole: Hugh Marshall Cole (July 14, 1910 – June 5, 2005) was an American historian and army officer, best known as the author of "The Lorraine Campaign" and "The Ardennes: Battle of the Bulge", two volumes of the U.S. Army official history of World War II.

Lorraine Campaign: Lorraine Campaign is a term used by U.S. Army historians to describe operations of the U.S. Third Army in Lorraine during World War II from September 1 through December 18, 1944.  Official U.S. Army campaign names for this period and location are "Northern France" and "Rhineland".  The term was popularized by the publication of a volume of the same name by the U.S. Army in 1950.  As written by the volume's author:

Ouvrage Otterbiel: Ouvrage Otterbiel forms part of the Maginot Line in the Fortified Sector of Rohrbach, Sub-sector of Bitche, and is located on the "Camp de Bitche" of the French Army.  It is located between "gros ouvrage" Schiesseck and "petit ouvrage" Grand Hohekirkel.  Part of the Fortified Sector of Rohrbach, the "petit ouvrage" comprises four combat blocks and an entry block.  Due to budget restrictions, a planned flanking infantry block was never constructed.  Otterbiel saw no significant action in the Battle of France, and limited action during the 1944/45 Lorraine Campaign.  It was renovated for use during the Cold War.  Otterbiel is used for ammunition storage by the French Army.

Battle of Fort Driant: The Battle of Fort Driant was a constituent battle in the 1944 Battle of Metz, during the Lorraine Campaign and the greater Siegfried Line Campaign.  The battle was on occupied French territory between the forces of the United States Third Army under the command of General George S. Patton and the forces of Nazi Germany under General Otto von Knobelsdorff.

Ouvrage Bois-du-Four: Ouvrage Bois-du-Four is a lesser work ("petit ouvrage") in the Fortified Sector of the Crusnes of the Maginot Line.  The ouvrage consists of a single large combat block without an underground gallery system, and is located between "petit ouvrage" Mauvais-Bois and "gros ouvrage" Bréhain, facing Luxembourg.  A planned expansion, never carried out, was intended to enlarge Bois-du-Four into a fully equipped "gros ouvrage".  Bois-du-Four saw little action in either the Battle of France in 1940 or the Lorraine Campaign of 1944.  It is preserved by the community of Villers-la-Montagne and may be visited.

Ouvrage Bréhain: Ouvrage Bréhain is part of the Fortified Sector of the Crusnes of the Maginot Line, located near the community of Bréhain-la-Ville in the Meurthe-et-Moselle "département" of France.  Bréhain is flanked by "petits ouvrages" Mauvais Bois and Aumetz.  The "gros ouvrage" was equipped with long-range artillery, and faced the border with Luxembourg.  It saw no major action in either the Battle of France in 1940 or the Lorraine Campaign of 1944.  While not open to public visitation, it has been secured and is in relatively good condition when compared to other abandoned Maginot positions.  A flanking casemate has been restored and may be visited.

Supporting paragraphs: Lorraine Campaign Operation Undertone
Answer: World War II