Why did Luxembourg abandon perpetual neutrality after World War II?

Luxembourg abandoned its policy of perpetual neutrality following the experiences of World War II, during which the country was invaded and occupied by Germany for the second time in the 20th century.12

After its liberation in September 1944, Luxembourg shifted its foreign policy toward active participation in international organizations to ensure its security and economic stability. This transition was formalized through its involvement in the Brussels Treaty of 1948 and its role as a founding member of the North Atlantic Treaty Organization (NATO) in 1949. By joining these collective defense and security frameworks, Luxembourg moved away from its previous status of neutrality, which had failed to protect its sovereignty during wartime.12