Neutrality was protection only while belligerents allowed it

Norway and the Netherlands could look back at the First World War and conclude that a neutral declaration had kept invasion away. Norway's experience had already included British pressure to sell supplies at a premium under threat of seizure, so neutrality had always depended on what belligerents would tolerate. Their later enthusiasm for NATO reflected how badly the broader expectation failed in the next conflict. Sweden and Switzerland provide a sharper contrast because neutrality was supported by mobilized forces, difficult geography, and sustained defense preparation. Sweden also invested in indigenous military technology and armed ships suited to its own security needs, while Switzerland could use mountainous terrain to absorb an invader's strength. Forms of unrestricted warfare long inflicted outside Europe had returned to the continent, weakening any assumption that neutral rights would be preserved out of chivalry.