A chain of defensive fortifications built by France on its eastern border between World War I and World War II. The Maginot line was designed to stop any future invasion by Germany, but it was never completed. In World War II, the Germans conquered France by going around the Maginot line to the north.
Note: The expression Maginot mentality refers to any military strategy that is exclusively defensive and therefore flawed. It also refers to military planning that is aimed at the past. This way of thinking is sometimes referred to as “fighting the last war.”