I think we may have discussed this before, but there are indeed a large number of expressions and idioms in the English language that involve the word "Dutch". I found a list on a Dutch website (that's not one of the phrases, and the site is in English). The article says that most of these terms came into use in the 17th century when there were many conflicts between England and the Netherlands, and the Netherlands lost the Dutch colony which later became New York. As They Might Be Giants once sang, "Even old New York was once New Amsterdam."
Some popular examples are: a Dutch auction, Dutch courage, talking double Dutch and to go Dutch (a Dutch treat).