Historically of course the Zionist movement has often worked with Nazis against the common foe e.g. the Gestapo/Hagannah agent Feivel Polkes (whose file to this day is kept closed in Israel).The above sentence is simply inaccurate.
1. Greenstein claims that the Polkes file is closed in Israel. We already know that Greenstein lied about reading Francis R. Nicosia's latest book, Zionism and Anti-Semitism in Nazi Germany. Claiming to have read it, he was forced to admit otherwise. Had Greenstein actually read it, he would be aware that Nicosia had clearly used the Haganah archive in Tel Aviv for information. Moreover, I have in my possession a copy of the "Secret Document of the Berlin Security Police Concerning Feivel Polkes of Tel Aviv" dated June 17, 1937. The clear stamp on my copy reads "The Central Archives for the Disaster and the Heroism, Yad-Washem, Jerusalem." There is therefore plenty of information available in Israel on Polkes.
2. Greenstein uses the example of Polkes to suggest that the Zionist movement worked with the Nazis. Here we need some historical context. In 1937 there were many Jews living in Nazi Germany. At that point in time the Nazis wanted the Jews out of Germany and Polkes, who worked for the Jewish self-defense organization in Palestine, the Haganah, had contact with a Nazi agent Franz Reichert who suggested to Polkes that there was a possibility of a substantial increase in Jewish emigration from Germany to Palestine. As a result of this contact Polkes traveled to Berlin where he met Eichmann and other Nazis and tried to convince the Nazis to allow Jewish emigration from Germany to Palestine. Following this meeting, Eichmann with his accomplice Hagan traveled to Palestine and on to Egypt. It was in Egypt that Eichmann met Polkes and where Polkes suggested ways of increasing Jewish emigration from Germany to Palestine.
Had Polkes been successful in his endeavour, many more Jews might have been saved from their ultimate fate at the hands of the Nazis, but as Nicosia mentions, "Nothing of substance ever came from this contact."
Greenstein has used the example Polkes of the Zionist movement working with the Nazis. What Greenstein does not reveal is that it emerged in a subsequent interview with Polkes that the Haganah did not favour Polkes trip to Berlin. Shaul Avigur from Haganah's illegal immigration department also confirmed that Polkes's trip not requested by the Haganah. And as Nicosia comments, Polkes's brief encounter with Eichmann "came under severe criticism within the Haganah after his return to Palestine, and he was eventually relieved of his responsibilities in the organization."
All this can be seen on pages 123-126 of Francis R. Nicosia's latest book.