Final answer:
Belgium was overrun by German forces in 18 days during WWII, from May 10 to May 28, 1940. In WWI, it took approximately 16 days for most of Belgium to be under German control, starting from August 4, 1914. The German invasion included severe resistance, civilian casualties, and marked Germany as the aggressor.
Step-by-step explanation:
Belgium was overrun by German forces in a span of 18 days during World War II, as the invasion began on May 10, 1940, and was complete by May 28, 1940. In World War I, the German invasion started on August 4, 1914, and by August 20, 1914, most of Belgium was under German control, although pockets of Belgian resistance continued.
The expectation of a swift surrender by Belgium in both World Wars was proven wrong. Belgian soldiers put up a fierce resistance, but they were ultimately outmatched by the German military's superior numbers and tactics. The German invasion breached Belgium's neutrality and led to widespread destruction, civilian massacres, and violations of international treaties.
In World War II, the Wehrmacht's rapid advance into Belgium was part of a larger strategy to bypass the heavily fortified Maginot Line and strike at France swiftly. This maneuver was a critical element of the blitzkrieg tactics that led to the fall of France. The disregard for Belgian neutrality and the brutality of the occupation had profound effects on the civilian population and contributed to the portrayal of Germany as the aggressor in both global conflicts.