The Dutch resistance to the Nazi occupation of the Netherlands during World War II can be mainly characterized by its prominent non-violence, peaking at over 300,000 people in hiding in the autumn of 1944, tended to by some 60,000 to 200,000 illegal landlords and caretakers and tolerated knowingly by some one million people, including a few incidental individuals among German occupiers and military.
Dutch resistance developed relatively slowly, but the event of the February strike and its cause, the random police harassment and deportation of over 400 Jews, greatly stimulated resistance. The first to organize themselves were the Dutch communists, who set up a cell-system immediately. Some other very amateurish groups also emerged, notably De Geuzen , set-up by Bernard IJzerdraat and also some military-styled groups started, such as the Order Service, . Most had great trouble surviving betrayal in the first two years of the war.
Dutch counterintelligence, domestic sabotage, and communications networks eventually provided key support to Allied forces, beginning in 1944 and continuing until the Netherlands was fully liberated. Some 75% (105,000 out of 140,000) of the Jewish population perished in the Holocaust, most of them murdered in Nazi death camps. A number of resistance groups specialized in saving Jewish children, including the Utrechtse Kindercomite
the Landelijke Organsatie voor Hulp aan Onderduikers, the Naamlooze Vennootschap, NV and the Amsterdam Student Group. The Columbia Guide to the Holocaust estimates that 215–500 Dutch Romanis were killed by the Nazis, with the higher figure estimated as almost the entire pre-war population of Dutch Romanis.
Prior to the German invasion, the Netherlands had adhered to a policy of strict neutrality. The country had narrow bonds with Germany, and less so with the British. The Dutch had not engaged in war with any European nation since 1830. During World War I, the Dutch were not invaded by Germany and anti-German sentiment was not as strong after that war as it was in other European countries. The German ex-Kaiser Wilhelm II had fled to the Netherlands in 1918 and lived and died there in exile. The German invasion on May 10th 1940 therefore came as a great shock to many Dutch people. Nevertheless, the country had ordered general mobilisation in September 1939. By November 1938, during the Kristalnacht , many Dutch people received a foretaste of things to come; German synagogues could be seen burning, even from the Netherlands. An anti-fascist movement started to gain popularity – as did the fascist movement, notably the Nationaal Socialistische Beweging (NSB), under Anton Mustert.
Despite strict neutrality, which implied shooting down British as well as German planes crossing the border into the Netherlands, the country’s large merchant fleet was severely attacked by the Germans after 1 September 1939, the beginning of World War II. The sinking of the passenger liner SS Simon Bolivar in November 1939, with 84 dead, especially shocked the nation. It was not the only vessel.