Marne
the Marne River
Difficult to say about the strategic bit. Certainly the Marne & the Somme, the Aisne too. Verdun is in the valley of the Meuse. The Isonzo in northern Italy saw much fighting, notably at Caporetto.
In World War 1 (1914-1918) the Oder was of strategic significance at all.
The Marne River in France. It was about sixty miles from Paris and it was twice the location of a final and successful defensive stand to keep the Germans out of Paris.
the somme
Yes, trenches were used as a strategic defense tactic during World War II.
TheOfficeof Strategic Services
There were several, but the really important one was the Marne.
Latin America was the strategic backyard of the US during the Cold War. The Cold War started after World War II and lasted until 1991.
No, losing control of the Mississippi River was the most major strategic loss of the war.
The Marne River.
Because it was the first war where aircraft had a decisive, strategic effect on the course of the war.