While I agree with just about everything he says, I do disagree to a point.
There is a deep lesson in Purim. It is not just that the Jewish people must rely on their might to fight against enemies who rise against us. Purim is a very spiritual and deep holiday. It is said of Purim that Yom Kippur, the holiest day of the Jewish year, is a day like Purim (Yom Ha KipPurim). While we fast on Yom Kippur we feast on Purim. The Jewish people were only set to be exterminated because of their own transgressions, as we are told by the sages that the KING is actually Hashem, who decreed our fate. But because of the righteousness of Mordechai, the gadol of the generation, and because of Esthers bravery in the palace of the King, that the Jewish people were able to merit being redeemed from the decree. It would be foolish to believe that they could have fought against the decree of the King. The King had decreed that on Adar 14 that all Jews, men women and children, were to be killed in every city. Any non-Jew who tried to help a Jew, and any Jews in a town were left alive, the entire town would be razed to the ground by the Kings mighty armies. It is only because of Mordechai's chance encounter with the plotters against the King, and that the King couldn't sleep at night and was read from the book of chronicles, that Mordechai saved the king, that the events started to reverse for Haman, and the future of the Jews was assured.
I feel a great pride in the ability of the Jews to rise up against the plotters of the extermination of the Jews. But it would not have been possible if not for the King reversing the decree, only because of Esthers party where she exposed Haman for the Rasha (wicked one) he really was. But I will always remember the lesson, to give gratitude to the King of Kings, Hashem who's hidden hand in the Purim story is the real star.
So while I agree that some have muddied the message of Purim, I also feel that saying that only by our having a strong army will make us impervious to our enemies attacks. What we need is a very firm faith in the providence of our G-d. It is said that the Jewish people re-established their marriage contract with Hashem on Purim, the contract which was originally made at the foot of Mount Sinai when we received the Torah. We made that contract under the threat of death (when Hashem held the mountain over us). But on Purim we accepted Hashems relationship because of genuine love for his caring love.