Our rabbi, Rabbi Bassous, gave 5 reasons why the rabbis chose to celebrate the miracle of the oil on Chanukah. An alternative question might be: Why emphasize the oil instead of the military victory?
(My apologies if I restate any of his talk incorrectly).
- Humility: in crushing the olive to make the oil, we learn humility. We should learn to be humble in our lives.
- Permeation: Oil permeates the skin if we rub it like an ointment. Just as Joseph was involved in Egypt in a good way, so we Jews should be involved in the world around us.
- Water and oil separate: water does not mix with oil. We should not mix in and dissolve in greater society. Joseph was involved in Egypt, but he retained his Judaism.
- Oil floats to the top: if we are good, hardworking people, we can rise above in society.
- Light unto others: the lighted oil is symbolic of being a light unto others.
If you need further explanation or elaboration, feel free to ask the comments (especially if you don’t celebrate Chanukah or if you just don’t understand one part of what he said – I’m open to questions).