Sefer Devarim is called "Mishneh Torah – The Review of the Torah" because it repeats over 100 mitzvot already mandated in the previous 4 Books. Rav S.R. Hirsch explains that of the 199 Mitzvot commanded in this book, more than 70 are new. The repeated Mitzvot focus on areas that will be of greater immediate concern as they encounter the 7 Nations. For example, the prohibition against idol worship. Although already taught, it needed to be reiterated as the Jews would confront the inhabitants of Canaan, who were idolatrous. Those mitzvot whose application was the same, whether in the desert or in the Land, are not reviewed. In Parshat Vaetchanan Moshe continues his final instructions to the Bnei Yisrael.
1st & 2nd Aliyot: Moshe beseeched Hashem to enter the Land. However, he seemingly blamed the nation when his request was turned down. Moshe explained the foundation of our divine mission, which will be recognized by the other nations. Moshe stressed allegiance to Hashem and the consequences to ourselves and our children if we do not keep the law.
3rd & 4th Aliyot: Moshe designated the Cities of Refuge, and reviewed the entire experience of Revelation.
4th, 5th & 6th Aliyot: Moshe stressed the reaction of the nation after te giving of the Torah, and forewarned them not deviate from the Torah, either to the right or the to the left. The first paragraph of Shema is recorded. (6:10-15) Moshe warned the people about the dangers of prosperity, and directed them to keep the commandments and remember the Exodus. Moshe forewarned them about the dangers of assimilation and told them to always remember that they are the Chosen People