In the context of a thread which was not discussing Israel, but discussing anti-Semitism in Europe and the U.S. to that point, the invocation of legions of Israel defenders and the confusion of anti-Semitism with opinions on Israeli policy is, clearly, motivated by one and only one thing.
Later on:
Again, the topic is simply the existence of anti-Semitism in Europe or the U.S., using examples such as rocks being thrown at a school bus in New York. To bring up “the line dictated by the Israeli Government and their devoted American brethren” [sic] is motivated by one and only one thing.