More background; in World War 1, Holland was a bit “leaky” in regard to the blockade. The Germans tried to route imports through Dutch ports. The Brits caught on very quickly, and extended a “quarantine” on Holland. Even though she was neutral, the British determined how much they “needed” in terms of imports, and seized as contraband anything over that.
No wonder they gave the Kaiser sanctuary. On the other hand, in World War 2, you would think the Germans would have maintained the same neutrality, but I guess not.