The Talmud (Shabbat 24a) questions whether Al Hanissim", inserted into the tefillah on Chanukah, should also be integrated into Birkat ha-Mazon in order to further promote pirsumei nisa (despite the fact that Chanukah is only a rabbinic festival). The Talmud's conclusion is somewhat ambiguous: "amar Rav eino mazkir, ve-im ba lehazkir mazkir be-hodaah...ke-tefilah mah tefillah be-hodaah af Birkat ha-Mazon be-hodaah." After initially rejecting this proposition, the Gemara subsequently permits it albeit in a manner that registers ambivalence, certainly that is far short of an unequivocal endorsement, emphasizing instead that it must be located in the hodaah section of Birkat ha-Mazon , parallel to its location in tefillah. Indeed, the Chachmei Ashkenaz (see Mordechai no.279 also citing Ravyah's view, Hagahot Maimuniyot, Berachot 2:7 etc.) rule that Al Hanissim's insertion into Birkat ha-Mazon is merely a reshut (though they debate whether its wide acceptance does not turn it into a requirement). [In fact, the consensus of baalei halachah mandate this practice and perceive it as a significant expression of Chanukah hodaah. I hope to elaborate this phenomenon at another time.]
However, it is noteworthy that the Rambam (perhaps following Rabbeinu Hananel's reading of the sugya) presents the recitation of Al Hanissim in Birkat ha-Mazon as a requirement. His language and treatment of Birkat ha-Mazon (Hilchot Berachot 2:6) and tefillah (Hilchot Tefillah 2:13) are completely parallel (though he only mentions in the context of Birkat ha-Mazon-Berachot 2:13 that the omission does not disqualify). While he also accentuates the hodaah location link between them, his formulation - "beChanukah u-purim mosif be-emtza birkat haaretz Al Hanissim ke-derech shemosif be-tefillah" connotes a more substantive equation. What accounts for the Rambam's expansive ruling? [It is noteworthy that Rambam omits any discussion of Al Hanissim in Hilchot Chanukah, and evidently does not interpret "hodaah" in Shabbat 21b as a reference to this recitation, in sharp contrast to Rashi. It is intriguing to consider the relationship between these factors.] We may better appreciate his stance by contrasting it with a different perspective.
The Rishonim were troubled by the gemara's implicit assumption that Al Hanissim is more relevant to tefillah than to Birkat ha-Mazon . While the Baalei Tosafot (s.v. Mahu) attribute the discrepancy to the public framework of tefillah that is more conducive than the private context of Birkat ha-Mazon to the promotion of pirsumei nisa, Rashi (s.v. beBirkat ha-Mazon) apparently invokes a more fundamental consideration. He states as follows: "be-tefillah peshita lan she-harei le-hallel u-le-hodaah nikbikbeu ke-deamrinan le-eil" Evidently he alludes not merely to a previous Talmudic passage, but specifically to his singular interpretation of that passage.
The Talmud (Shabbat 21b) characterizes Chanukah as a time of "yom tov, hallel and hodaah." Rashi (s.v. Hachi Garsinan) explains that the term "yom tov" in this context does not constitute an independent motif of Chanukah, as there is no prohibition to engage in melachah on these days, but merely establishes that this festival is uniquely dedicated to hallel and hodaah, which he renders as the recitation of Al Hanissim! Rashi's neutralization of the yom tov motif of Chanukah was evidently very impactful. Maharam of Rothenberg ruled that there is no obligation to feast on Chanukah inasmuch as there is an absence of simchat yom tov. The Bach and Levush (Orach Chaim no. 670) probe why feasting, such a central theme on Purim, is inconsequential on Chanukah. They posit (each in a very distinctive manner) that while Purim celebrates the salvation of Klal Yisrael from the threat of physical annihilation and is thus commemorated in an intensely physical fashion, the Chanukah miracle that symbolizes salvation from spiritual extinction, appropriately accentuates a focused spiritual program of hallel and hodaah. Thus, tefillah, amidah lifnei Hashem, the consummate avodah she-belev, is a far more compelling framework for Al Hanissim-hodaah than Birkat ha-Mazon . [Indeed, the Bach underscores the link to avodah she-belev!]
In this light, we may return to our analysis of the Rambam's view. In his formulation-rendition of the themes in Shabbat 21b - yom tov, hallel ,hodaah, Rambam (Hilchot Chanukah 3:3) (unlike Rashi) delineates three distinct motifs: simchah, hallel, and hadlakat neirot (on the latter as an interpretation of hodaah, see my article in Torah Web, Chanukah: A "Yom Tov" of Hallel and Hodaah.) The Maharshal (Yam Shel Shlomoh, Bava Kama 7:37) disputes Maharam's ruling that Chanukah meals fail to attain the status of seudat mitzvah, arguing that Rambam's rendering of "yom tov" as simchah, elevates the halachic status of Chanukah meals! We may now suggest that according to the Rambam's consistent view, Birkat ha-Mazon , like tefillah, is an appropriate, indeed a compelling vehicle and framework for Al Hanissim.
The divergent views of Rashi and Rambam are equally compelling. While Rashi's interpretation of a hodaah-hallel focused "yom tov" and his ambivalent view on Al Hanissim in Birkat ha-Mazon underscore the singular spiritual emphasis of Chanukah, it is likely that Rambam fully subscribed to this focus, as well. His expanded survey (Hilchot Chanukah 3:1, see also Hilchot Yesodei ha-Torah 5:3) of the scope of the conflict and the nature of the threat to religious integrity reinforce this impression. The Rambam's presentation conveys a powerful truth: absent the integrity of halachic life, physical survival is stripped of its viability. This perspective underpins the principle of mesirut nefesh and justifies the Chashmonaim decision to engage in battle rather than succumb. The fact that spiritual salvation also triggers a physical simchah-seudah yom tov-esque halachic response, validating a mandatory Al Hanissim even in Birkat ha-Mazon is inspiring, indeed.