The explanation by Mr. Luyis did not extinguish William I's anger; instead, it grew more intense.
The Kingdom of Prussia was heavily guarded, fearing the French Empire's incursion into German territory. However, it still failed to prevent the French Empire from striking at their home.
The territory of the Grand Duchy of Luxembourg, though only the size of a free city in the German Region, is one of the vital military fortresses guarding against a French invasion. The loss of Luxembourg enlarged the boundary where the Kingdom of Prussia was adjacent to the French Empire, increasing the military pressure Prussia had to bear significantly.
Of course, the military pressure on Prussia was not the worst issue. The most troublesome point was that while the French Empire secretly negotiated with the Kingdom of the Netherlands, the Kingdom of Prussia didn't pick up any indication of this.
