"Mishenichnas Av memaatin be-simcha" (Taanit 26b). It is evidently insufficient merely to properly observe Tishah b'Av; it is necessary to actively and extensively prepare for this day. The calibrated, progressive expressions of national mourning in advance of 9Av (for Ashkenazim especially: 3 weeks, nine days, shavuah she'chal bo, 9Av-tosefet, night, pre-chatzot, post-chatzot, till chatzot of 10Av) serve a double function. On the one hand, they reflect an extended period of collective grief and communal introspection (in the spirit of "midarkei ha-teshuvah"- Rambam, Hilchot Taanit 1:2), beginning bein hametzarim and extending to chatzot after 9Av. At the same time, this advanced anticipation and elaborate process is designed to effectively facilitate an appropriately intense, acute sense of profound loss on the double anniversary of the churban ha-bayyit, the apex of national calamity. To attain an authentic emotional response to aveilut de-rabbim and yeshanah (Yevamot 43b), historically distant and collectively diffused, requires progressive, concentrated immersion in the various protocols of aveilut. Only these will stimulate an acute, profound sense of individual and collective calamity, notwithstanding personal experiential distance from the events that engender the obligation.
The very capacity to truly, viscerally experience loss and pain due to the churban, attests to and furthers our national identification with and the authentic unity of Klal Yisrael, as it implicitly reflects and reinforces our appreciation for the central role and indispensable contribution of Eretz Yisrael and the Mikdash in Jewish life. Given these deeply rooted emotions and convictions, it is no wonder that the destruction of our national institutions engenders feelings of crisis that stimulate the sense of being diminished and bereft. Elsewhere (see TorahWeb, Tishah b'av 2016, and also TorahWeb, Tishah b"av 2001), we have elaborated on the theme, developed by Chatam Sofer and others, that 9Av's status as a "moed" (Eichah 1:15) also entails the glimmer of nechamah (consolation) implied and enhanced by an appropriate observance of this national mourning. Indeed, the commitment to national destiny and the cultivation of national empathy significantly contribute to reversing the churban's effect, paving the way for a lasting geulah.
The capacity of Klal Yisrael, collectively and even individually, to experience impoverishment and desolation on this day is encapsulated by an extraordinary view and formulation of the Ramban in, significantly, a strictly halachic context.
Addressing the issue of the viability of havdalah on a kos on motzai Shabbat Tishah b'Av (as the fast has already begun), the Ramban (Torah ha-Adam, Chavel ed., pp260-261; see also Rosh, Taanit 4:40) rejects the position of the Behag that one should postpone Havdalah until Sunday evening after the conclusion of the fast. He argues that a Havdalah delayed more than a day constitutes tashlumin, which is necessarily contingent upon the obligation and fundamental capacity to implement the obligation in its appropriate time. The legal obstacle to executing Havdalah on a kos motzai Shabbat due to the fast, inherently disqualifies any tashlumin. [Rosh, op cit, addresses a parallel issue regarding an onein who was excluded from the initial obligation of Havdalah. It is reasonable to distinguish between different exemptions or exclusions, as well as between different time frames for fulfilling this mitzvah. The Rosh proposes to differentiate between the onein and Tishah b'Av exclusions. The Ramban, weighs the relationship between different times to compensate for having missed havdalah.] He further dismisses the suggestion that a minor drink the Havdalah wine, based on the principle established regarding birkat hazeman on Yon Kippur that this exception will be misconstrued and lead to the erosion of the prohibition against eating and drinking (Eruvin 40b-"ati le-misrach").
Finally, Ramban expresses his own conviction that Havdalah on a kos is not required under these circumstances, as one can properly accomplish Havdalah on this night through tefillah. He explains that the institution of havdalah al hakos was established only when Klal Yisrael attained a measure of stability, confidence, and affluence (he'eshiru, keva'uhu al ha-kos), a state that is completely incompatible with the visceral emotions of impoverishment, inadequacy, and persecution (kol Yisrael aniyim merudim heim, vechi hai shaata lo tiknu al ha-kos kelal...she-ein kos ba-olam ein zarich le-havdil) that prevail on this day of national mourning. The emphatic assertion and unambiguous halachic assessment that all Jews are fundamentally diminished on Tishah b'Av, legally excluded from the enactment of Havdalah on a kos, attests to the aspiration and capacity of national and historical Jewish identification and commitment.
While normatively we adopt the halachic ruling of the Behag, Rosh (Taanit), and Tur (Orach Chaim 556), postponing havdalah until motzai Tishah b'Av, Ramban's insightful and emotionally demanding perspective resonates powerfully. It inspires optimism that a genuine and deeply-felt aveilut de-rabim ve-aveilut yeshanah is achievable, and that its attainment will pave the road to a geulah sheleimah be-karov.