One of the most well-known questions raised in regard to the miracle of Neiros Chanukah is that of the Rav Eliyahu Mizrachi (commentary to the smag; see also Pnei Yehoshua Shabbos 21b). The Re’em points out that the Gemara tells us that when there is no other choice, one may use impure oil for the lighting of the menorah (as a part of the general rule of “Tumah Hutra B’tzibbur”). If this is so what was the purpose of the miracle of the oil lasting eight nights? Could they not have used the remaining oils that were defiled by the invading Greeks?
Rav Asher Weiss (quoted in K’motzei Shalal Rav pg. 304) gives a novel explanation. The Greeks were a unique type of enemy. They were not traditional “anti-Semites” who wanted to kill the Jews or even destroy Jewish continuity. They did not attempt to destroy the Beis Hamikdash or expel the Jewish nation from the Land of Israel as so many before and after. The goal of Yavan was to destroy our identity in our own home. Rather than destroy the Beis Hamikdash, they wanted to it to continue being used but for what they wanted. They wanted Jews to continue living in the Land of Israel but without an authentic Jewish culture.
Indeed, the Chashmonaim could have used the impure oil to light. However, that would have been a victory for the Greeks. There is nothing they would have liked more that performing the Temple service in a way not authentic to Jewish tradition. Our ancestors relied on a miracle to have eight days of oil rather than give the Greeks this symbolic victory. They did not want to perform the mitzvah in its non-ideal form. The Chashmonaim wanted to do it in a mehadrin fashion, its most ideal form. That’s why Chanukah is a halacha that is specifically fulfilled in it’s mehadrin form. Although the Gemara gives a basic level of one candle every night, we fulfill it by lighting one more every night, which the Gemara terms mehadrin. The halacha serves to remind us that the miracle of Chanukah was not merely the oil lasting, but the conviction of Bnei Chashmonai to restore the Menorah service in its authentic and mehadrin form. It was this element of the miracle that served as the ultimate defeat of Greek culture.
Chanukah is about reclaiming the ideals of Judaism. The neiros remind us that our ancestors never surrendered even when they had an excuse to do so. The mitzvah is intimately tied to our house (see Gemara and Pnei Yehoshua Ibid) to remind us that we must only teach our families an authentic Yiddishkeit. One that captures that glory of mehadrin in all its majesty.