In parshat Devarim, Hashem tells the Israelites to leave the Edomites alone and bypass them: "You shall not provoke them, for I will not give you of their land...because I have given Mount Seir to Esau as an inheritance." [Deuteronomy 2:2-5] The Midrash says that Esau (later, Rome) was being rewarded for honoring his parents:
Rabbi Yehudah bar Sima said: [Hashem] saw [Esau] destroying His Temple and remained silent... [because Esau] still deserves reward for honoring his parents... The Holy One, blessed be He, said: "I am paying [Esau his] dues." [Deuteronomy R. 1:17] ... Command the heads of [all future] generations to treat [Esau] with respect. [Deuteronomy R. 1:20]
This sure is a big reward for honoring your father and your mother! One can almost understand Rome being given power and influence as a reward, but why should this reward include oppressing the Jews for 7 centuries, destroying their Temple and stealing their land?