As a newcomer to the Netherlands, I do many things wrong. I forget to bring gifts to dinner parties, I thank people too profusely, and often speak too personally with people I've just met. But no slip-up has provoked a more troubled response than when I've brought up my concerns about Santa Claus.

Here’s what concerns me: In Holland, Santa, or “Sinterklaas,” as he’s known to the Dutch, doesn't have reindeer; he has a little helper named Zwarte Piet, literally Black Pete, who charms children with pepernoten cookies and a kooky demeanor while horrifying foreign visitors with his resemblance to Little Black Sambo. Each year, on Dec. 5, the morning before the feast of St. Nicholas, children all over the country wake up excited for gifts and candy while thousands of adults go to their mirrors to apply brown paint and red lips. In their Zwarte Piet costumes, they fill central Amsterdam and small village streets, ushering in the arrival of Sinterklaas who, in the Dutch tradition, rides a flying white horse.

Trying to tell a Dutch person why this image disturbs you will often result in anger and frustration. Otherwise mature and liberal-minded adults may recoil from the topic and offer a rote list of reasons why Zwarte Piet should not offend anybody. “He is not even a black man,” many will tell you. “He is just black because he came down the chimney.” Then, you may reply, why aren’t his clothes dirty?...