This coming Shabbos, when we read Parshas Ki Savo, we will be fulfilling a double mitzvah: 1) We will be reading the parshas hashavua 2) We will be fulfilling the special takannah made by Ezra, i.e., to read the tochacha of Ki Savo soon before Rosh Hashana.
Achronim point out that it would appear from the Talmud that even when the practice was to have a tri-annual cycle of Torah reading, so that Simchas Torah only occurred once every three years, and Parshas Ki Savo did not fall out near Rosh Hashana, the tochacha would still be read, as a special kriah soon before Rosh Hashana (similar to the reading of Parshios Zachor and Parah.)
In the concluding pasuk of the tochacha, we read that the Jewish people entered into this contract with G-d in addition to the original agreement (appearing in Parshas Bechukosai) that was proclaimed at Har Sinai. The question begs itself: why was there a need for an additional bris (covenant)? Why wasn't the first contract binding?
The answer to this question appears in the chumash itself in the opening pesukim of Parshas Nitzavim. In these pesukim Moshe specifically indicates that this covenant entered into between Bnai Yisrael and G-d prior to Moshe's death involves not only the Jews currently there, but all future generations: "Velo itchem levadchem...ki et asher yeshno po imanu omed hayom lifnei Hasham elokeinu, veet asher einenu po imanu hayom," (29:13-14). This statement implies that the first covenant, that which took place at Har Sinai, was only binding between G-d and those individuals who lived in that generation.
In the text of the tochacha in Parshas Bechukosai, the Jewish people are referred to in the plural form because that bris was made with the many individual members of Klal Yisrael. In the tochacha in Ki Savo, however, the Jewish people are referred to in the singular. This "contract" was made with Klal Yisrael, and Klal yisrael is a simple entity which includes all of the Jews who lived throughout all the generations, starting from the trip of Avraham Avinu until Yemos Hamoshiach. The fact that all the souls were present at Maamad Har Sinai had an effect on all of us in a supernatural way. "Baavur yishma ho'om bedabri imach vegam becha yaaminu leolam" (Shemos 19:9), "Uvaavur tihiye yirato al peneichem levilti techetau," (Shemos 20:17).
But this was not enough to make the Torah laws legally binding on all future generations. After the forty years of travelling in the desert we finally became a nation. When the Jews crossed over the Jordan and entered Eretz Yisrael they completed this second bris. The bris began with Moshe Rabeinu at arvot moav and completed by his successor Yehoshua ben Nun at Har Gerizim and Har Aival. According to the talmudic tradition, the principle of, "kol Yisrael arevim zeh bazeh", did not begin to function until this bris was completed. That is when we became a nation.
In every generation there are individuals who chose not to keep the mitzvos. These people want to "be themselves" and "do their own thing". Truth of the matter is that whether we like it or not we are all part of Klal Yisrael. Keeping the mitzvos is "the natural thing" to do. When one chooses not to keep mitzvos, he is running away from his real self.
Every day in our prayers we mention the words of the prophet: "Veani zos berisi osam amar Hashem ruchi asher alecha udevarai asher samti beficha lo yamushu mipicha umepi zaracha umepi zera zaracha amar Hashem meata vead olam, " (Yeshayah 59:21). G-d has imposed His "bris" upon us. The navi did not say, "brisi etach" , My contract with you, but rather "berisi otach", ie., My bris is hereby being imposed upon you. You can never run away from the Torah. Even if for a generation or two people leave the Torah, "umepi zerah zaracha meata vead olam," ultimately the later generations will have to return. It is the natural thing to do. It will have to happen. The Rambam points out that the Torah has already promised us that ultimately the Jewish people will have to do teshuvah. All the future generations are part of Knesses Yisroel which entered into the second bris with Hashem.
Ezra's enactment (takanah) requires that we review this national commitment as contained in the bris in Ki Savo, every year prior to Rosh Hashana. Whether we like it or not this is part of our genetic composition. We are all part of Klal Yisroel, carrying on in that ancient tradition from Avraham Avinu. We must act in accordance with who we really are.