When studying the sources dealing with Channukah, there are many questions which surface.
I will first outline those questions, and then offer possible answers.

1) The Al HaNissim prayer of thanks included in our daily prayers and Birchat HaMazone primarily discuss the war. And at the end it makes mention of our kindling the lights, but does not mention the miracle of the oil. Does this mean that war is the essence of the day? What was the essential element in Channukah which the Rabbis deemed it to warrant holiday status? Was it the miracle that a few Jews overtook the myriads of Greeks in battle, the duration of the oil, both, or some other factor?

2) What was the purpose in the miracle of oil lasting 8 days? The principle of—ohness rachmana patreh—one coerced by situation is exempt—rendered the priests innocent for their inability to light the menorah. Since they were exempt from the obligation to light the menorah until they pressed new oil and were cleansed from the casualties, why did God create this miracle of the oil’s duration?

Can we suggest that the miracle of the oil is to reflect upon the war, that it was won via miracles? If so, why then does Rambam state that we won due to God’s salvation, even before discussing the oil? It would seem that Rambam held that the Rabbis understood our military victory to be caused by God. In such a case, the oil would be superfluous for teaching this. Unless we suggest that the military victory—although executed by God—was not an overt miracle, and itself would be no cause for a holiday. It would be no different than wars won by Joshua for example, when conquering Jericho, a day around which, the Rabbis did not create holiday. What then was so different about the battle of the Macabees or that entire event in general, that God decided to underline that event by the miracle of the oil, thereby showing such significance? There were many battles in which God made us victors. Yet in those many wars, God did not create an overt miracle after the fact, as is the case with Channukah.

Additionally, in his Mishneh Torah, Rambam indicates that until the miracle of the oil, the Rabbis would not have instituted the holiday based on military success alone. According to Rambam, what is it about the oil—or the war upon which it reflects—which demanded that Channukah be established as a holiday?

3) The Megilla is read on Purim as our halachik observance. The reasoning is that this specific element was the catalyst for the Jew’s salvation, as the Talmud in Megilla 12b states, “Had it not been for the first letter, not one remnant or escapee of Jews would have survived.” Meaning, since the Persians disqualified King Achashverosh’s credibility based on a previous letter, which was foolish in their eyes, they showed little respect for the King’s subsequent decree to destroy the Jews. Following this template for establishing a holiday, if the Rabbis established Channukah based on the success of the war, why is there no mention of the Channukah battle as part of our halachik performance? Lighting oil or candles is divorced from the battle. Why are these lights selected by the Rabbis as the performance of the halacha, and not something germane to the war, like carrying a sword or the like? Purim’s laws were organized around elements, which caused our salvation, namely the letter. Why are Channukah laws centered on a miracle subsequent to our salvation?

4) What is the concept of having “mehadrin”: the concept that there are multiple levels of fulfilling the obligation of Channukah flames, each more preferred than the previous? We do not see this concept in connection with the Megilla. Additionally, why focus on the 8-day element, to the point that 8 days became an essential aspect of our halachik performance, as we light for 8 days, but only read the Megilla on one day? Additionally, why does a single Channukah menorah satisfy an entire household’s halachik obligations, whereas this does not work in the case of Lulav? Here, each member must have his own four species?  

Although possible to enact a miracle in the war itself, God chose to enact a miracle in the lights to emphasize our adherence to the Torah commands as the essence of that event, not mere bodily rescue. Life alone is not our goal. It must be a life of Torah study and adherence. Without Torah, our lives are meaningless. Perhaps for this reason the Rabbis understood the oil miracle in this light, and sought to build the laws of Channukah around this reuniting of the Jews to their laws, illustrating thereby that the first act of Torah adherence after the war —lighting the menorah—was the goal of the victory.

This follows well with Purim, as we state therein, “kimu v’kiblu mah shekiblu kvar”, “they (the Jews) rose up and accepted that which they previously accepted”, i.e., the Torah. Purim was an event where the Jews saw that a life permeated with wisdom proved to be the source of their salvation, as Mordechai’s and Esther’s cunning plan saved the Jews. The statement of “kimu v’kiblu mah shekiblu kvar” displays again that mere victory is not the goal, but rather, the highlight of that military success was the re-acceptance of Torah. Channukah is therefore celebrated via lights (the goal of the victory) which was the reestablishment of the Temple.

The Talmud in Shabbat asks, “What was Channukah established upon?” Meaning according to Rashi, “upon which miracle?” This Talmudic question addresses our question: answering, that without a miracle, military success would not qualify as a holiday. Only through the event of the miracle of the oil did the Rabbis deem Channukah worthy of institution as a holiday, and did so via lights, as this was the ‘goal’ of the victory. The essential miracle was the war, as it was the catalyst for our Torah adherence. So when offering thanks, we thank God for the success of the war, but not the lights. The lights are not that for which we are thankful. The lights are the reestablishment of our Torah. It was military victory, which demands thanks. The lights are used to recall the goal of the day through observance generation after generation. We make recourse to lights to pronounce the goal. However, it is the war alone for which we are thankful.

What was present in Channukah, which surpassed the battle at Jericho for example? Or when God stopped the Sun and Moon in Gibeon and Amek Ayalon respectively? All had miracles! Why then was Channukah established as a holiday, but not Jericho or other events, which included miracles? The answer could be the following: The miracle of the oil was subsequent to the war when we were already victors. All other wars, which contained miracles, had miracles for the sake of winning the war. The Rabbis may have perceived the fact that God enacted a miracle unnecessary for salvation as a Divine indication that Channukah was different, and worthy of institution as a holiday. (A Rabbi once discussed another difference, that during Channukah, the Greeks sought to strip us of our Judaism, not so in other wars, where the enemy simply was fighting for land.)

The element of a subsequent miracle (not necessary for salvation) compounded with our salvation from religious oppression (not mere military victory) were recognized by the Rabbis as grounds for instituting Channukah as a holiday. That special quality of God’s salvation from oppression, enabling us to follow the Torah also existed during Purim. Therefore we have only two holidays subsequent to the giving of the Torah; Purim recalls our bodily salvation, whereas Channukah recalls our religious salvation.

While discussing this further with Rabbi Mann, we came to the observation that “holiday” means that which is instituted for generations to observe. This needs explanation, as it would have sufficed to celebrate Channukah just that one year. The concept of a perpetual celebration must be adding another point. That is that the future celebrants have what to celebrate, somewhat on par with those who actually experienced the salvation so long ago. What do we—the future celebrants—have in common with the Jews alive at that event? It is that our existence and ability to practice our laws is a direct result from the miracles of Channukah. As we are direct beneficiaries, we must also show thanks to God for these acts of kindness. This also explains why Passover has two models: “Passover of Egypt”, and “Passover for Generations.” We see this idea is consistently part of our laws. 

The concept of mehadrin—beautification—teaches us that there are levels of fulfilling the obligation of Channukah. The reason mehadrin exists for few commands is as follows: When a Torah obligation deals with qualitative act, such as donning tefillin, one either dons them or does not. There is nothing more to be added after one has put on tefillin, you cannot wear tefillin “more” once they are on. A quantitative increase is impossible, you either wear them or you don’t. The same applies to kosher, either one eats kosher or he doesn’t. But an act, which is of a quantitative measure, is different. Such acts as discussing the Exodus, Channukah lights, and purchasing a finer Esrog, all lend themselves to quantitative increase. One may discuss the Exodus until morning, or buy a better Esrog, or light multiple candles. But there still must be sound reasoning behind such increase.

There is one goal with the lighting of the candles: to publicize the miracle to others. There are two ways in which we can increase this publicity: 1) more individuals spreading the story through multiple menorahs, and 2) increasing the content of the story publicized, which is achieved by increasing the number of lights each night. This teaches a passerby that there were a number of days that the miracle lasted, teaching a new element. By lighting only one candle each night, all one knows when he sees a menorah is that there was a miracle of Channukah. But if he sees five candles on the fifth night, he now learns something new: there were many days to the miracle. This increases the content of the story taught through the lights.