The reason many Charadie do not fight, as I have explained numerous times also, is because they do not recognize the secular Jewish state as having any religious standing to exist. There is a concept in Judaism called the 'Three Oaths' which establish promises that the Jewish people make to Hashem concerning the Exile from the land. One of these oaths is not to take the land by force, against the will of the nations of the world. Some of these Charadie sects have been in the land from long before the modern state was established (1948) some go back to the medieval times (12-1500) during the 1st aliyah. When the secular zionists created the state they did not recognize it as the actual beginning of the redemption because secular zionists do not keep the Torah, they violate many of the commandments (Shabbat and Yom Tov most vividly) and they look down on the religious Jews... In some ways I understand why they are anti-Zionist.
I am happily a religious Zionist who believes that the redemption has begun. I believe that the three oaths were violated by the nations of the world because one of the oaths is that the nations not oppress the Jewish people too harshly (and we have repeatedly been oppressed brutally during these 2000 years of exile). I rebuke those Jews who cling onto the three oaths as a reason to reject the modern state.