The way it works is, historically there has been a certain group of Jews, particularly in Germany, who believed the best way to get along and prosper was to downplay references to their Jewishness. They did not want to have anything to do with Jews (notably from Eastern Europe) who sought to maintain their Jewish traditions and culture. According to their perception, open displays of Jewish culture, or support for Jewish causes, was sure to generate anti-Semitism and thus undermine the gains they had achieved in European society.
A prominent example of this is the Sulzberger family that owns the New York Times. As you probably know, all during the second World War, the New York Times suppressed references to the Holocaust, because they didn’t want to be viewed as a “Jewish” newspaper. Also, during the second World War, some very prominent Jewish families opposed attempts to get the Roosevelt administration to permit more Jewish immigration into the US that would have allowed more Jews to flee the Holocaust, because they felt more “unassimilated” Jews would increase anti-Semitism and undermine what these families had achieved.
A current example of this attitude was displayed very recently by Peter Gelb, the Managing Director of the Metropolitan Opera, whose father was a very high-level executive at the New York Times whose beliefs about “Jewishness” appear to have rubbed off on his son.
When a group of prominent Rabbis visited Mr. Gelb in order to convey to him their feelings about the anti-Semitic opera, “The Death of Klinghoffer” that is scheduled to open this Monday, Mr. Gelb in effect told them to shut up - that their complaining would increase anti-Semitism and would be bad for the Jews. The Rabbis were very incensed that Mr. Gelb would presume to tell them what was good for the Jews.
So, as you can see, Jews are obviously not a monolithic group in their beliefs. Some are vehemently opposed to Israel (like the New York Times, which has opposed Israel since its inception), some are very strong supporters, some enjoy flaunting themselves as “good” Jews by engaging in anti-Semitic comments - there are all sorts.
I feel obliged to point out that the Sulzbergers converted to Episcopalianism decades ago. No great loss.