Of course, Yom Kippur and Tishah b'Av are nothing like each other. On both days we don't eat or drink, wear leather shoes, etc, but the days are of radically divergent spiritual characters.
On Yom Kippur we are [guardedly] optimistic; on Tishah b'Av we are miserable.
On Yom Kippur we are forgiven; on Tishah b'Av the world comes crashing down.
On Yom Kippur we declare our relationship with Gd, כי אנו עמך, "For we are Your nation"; on Tishah b'Av we say סתם תפלתי, "HaShem blocked my prayers."
But this year I came to an unsettling realization about a way in which Tishah b'Av and Yom Kippur do, indeed, run parallel to each other: They are both Days of Judgment.
Rosh haShanah is a day of judgment of each individual, and Yom Kippur is the day when each individual is again weighed. We prepare for the day by assessing our conduct, taking a personal accounting, and making amends and apologizing for our wrongdoing while trying to chart a more positive path.
And Tishah b'Av, it seems to me, is a day of judgment for the Jewish world. We are taught (Yerushalmi Yoma 1:1) that if the Beit haMikdash is not rebuilt in a generation's time, we view it as though the Beit haMikdash had been destroyed in that generation's time. So each Tishah b'Av, as we mark again the devastation of the Beit haMikdash, we are judged and we are found collectively guilty.
It's an unsettling thought, because we believe that every Yom Kippur ends with forgiveness for the individual, while every Tishah b'Av ends with a declaration of our community's guilt.
But then I had another thought: Why can't we end Tishah b'Av with forgiveness, as we do on Yom Kippur? What if we had, hypothetically, a leader who could deliver a "State of the Union" in the days leading up to Tishah b'Av, identify the elements needing fixing and apologize for wrongdoing, and so on?
Even if Tishah b'Av marks the time of Divine obscurity and blocked prayers, perhaps with proper preparation we could have a Tishah b'Av which ended with a Divine declaration of סלחתי, "I have forgiven," just as the original Tishah b'Av did? (Bamidbar 14:20)
Of course, such a thing is far from where we are today, in a world in which rabbis are assaulted by followers of other rabbis, in a world in which one Jew can easily call another Amalek, in a world in which… oh, forget it. You don't need me to run down the list of every bit of strife playing out on the Jewish world's polluted stage.
But maybe one day we'll turn Tishah b'Av into a national version of Yom Kippur.