The Miracle of the Oil
The only miracle discussed in Macabees is the military victory, the same miracle we talk about in the Al HaNissim. The small jug of oil first appears in the Talmud, codified about 600 years after the events of Chanuka. In the interim, a variety of rabbinic stories were told to answer the questions: (1) Why do we light candles on Hanukah? (2) Why is Hanukah 8 days? As you'll see, these stories show how the relationship between the Rabbis and the Hashmoneans changed over time:
"[At Hanukah] we commemorate the dedication of the Temple by the Hasmoneans who fought and defeated the Hellenists, and we kindle lights -- just as when [we] finished the Tabernacle in the Wilderness . . . ." (Pesikta Rabbati, ch. 6)
"Why do we kindle lights on Hanukah? Because when the sons of the Hasmoneans, the High Priest, defeated the Hellenists, they entered the Temple and found there eight iron spears. They stuck candles on them and lit them." (Pesikta Rabbati ch. 2)
"Why did the rabbis make Hanukah eight days? Because . . . the Hasmoneans entered the Temple and erected the altar and whitewashed it and repaired all of the ritual utensils. They were kept busy for eight days. And why do we light candles? Because . . . when the Hasmoneans entered the Temple there were eight iron spears in their hands. They covered them with wood and lit candles on them. They did this each of the 8 days." (Megilat Ta'anit ch. 9)
"What is Hanukah? When the Hellenists entered the Temple, they desecrated all of the oil. And when the Hasmonean dynasty grew and defeated them, they searched but found only one cruse of oil sealed with the stamp of the High Priest, and there was only enough in it to burn for one day. A miracle happened and it burned for eight days. The next year they made these days a fixed annual commemoration . . ." (TB Shabbat 21b; also Schol. Megilat Taanith 25 Kislev)
Why did the story change from a glorification of the military victory, to an oil miracle?
One easy answer (and beware of easy answers) is that the Rabbis wanted to demphasize the majesty of the Hasmoneans after they (the Hashmoneans) either (1) joined forces with the Sadducees and/or (2) presided over a civil war (ca. 67-61 BC) during which perhaps more than 100,000 Jews were killed. Support for this answer appears on the same page of Talmud where the oil miracle is first mentioned. On Shabbat 21b the Rabbis tell you that "in times of danger" Chanuka candles can be lit on a table: in other words, don't be a martyr like Judah and his brothers. Risking your life for the sake of Chanuka is not needed.
A second easy answer (same caveat) is that the Rabbis were wary of capricious rulers, and thought it wise to stay silent about that time we rose up and overthrew the ruling powers.
A third answer might seem more familiar to American Jews. The Mishnah has some brief references to the rules for Chanuka , indicating that by the end of the second century C.E. there was already a custom of kindling lights at the darkest period of the year. This was a custom that may have been imported from the northern latitudes during Roman rule -- perhaps in imitation of the Roman Saturnalia observances. Sometime between then and the completion of Gemara, the celebration of lights assumed greater significance and, just as today we elevate the observance of Chanuka in order to offset the influence of Christmas, the rabbis of the Talmud may have built up the idea of a miracle connected with lights, to show Jews that we had our own basis for a solstice observance.
Which is the right answer? No clue. Its one of the mysteries.