The Assyrian-Greeks sought to weaken the faith of the Jewish people and their observance of Torah and Mitzvos. The victory and miracle of Chanukah brought about a resurgence of faith and observance. This is similar to the objective of the Mitzvah of Hakhel: “That they learn… and fear Hashem… and observe all of the… Torah”
The miracle of Chanukah took place in the Beis Hamikdash where the Mitzvah of Hakhel was observed.
Hakhel took place on Sukkos, which is connected to Chanukah in a number of ways; They are both 8-day festivals. We recite the full Hallel for the entirety of both festivals.
According to Beis Shammai, the Chanukah candles should be lit in descending order; 8 on the first night, 7 on the second night etc. One of the reasons the Talmud brings is because the Chanukah candles are like the Bulls of the Musaf offerings of Sukkos which decreased in number each day.