Gentile (Christian?) Idolatry

I finished Idolatry, by Moshe Halbertal and Avishai Margalit.  I have two items, both pertaining to the issue of Gentile idolatry.

1.  On pages 210-213, Halbertal and Margalit talk about the question of whether Judaism considered Christians to be idolaters, and how that impacted the relationship between Jews and Christians during the Middle Ages.  Tractate Avodah Zarah in the Babylonian Talmud restricted relations between Jews and idolaters, including in the business realm.  Rabbinic authorities and Maimonides deemed Christianity to be idolatrous, on account of its belief in the Trinity and the incarnation, and the application of their teaching "prevented the Jews from doing business with the Christians at all" during the Middle Ages (page 210). 

Some Jews simply ignored these teachings and did business with Gentiles.  But there were others who sought to allow Jews to do business with Gentiles while being faithful to Jewish tradition.  One way was to appeal to Rabbi Tam's opinion (which is mentioned in the medieval Tosafot to Tractate Avodah Zarah 2a) that Jews can do business with Gentiles, so long as the object of their commerce is not used in an idolatrous worship service.  Another way was to refer to Rabbi Jochanan's view in Babylonian Talmud Chulin 13b that "Gentiles outside of the land of Israel are not idolaters, but they are merely following the customs of their ancestors" (Jochanan's words, as quoted by Halbertal and Margalit).  According to Halbertal and Margalit, the eleventh century rabbi Gershom Meor Hagolah, who cited Rabbi Jochanan's teaching, still believed that Christianity was idolatrous, probably because Jews were continually struggling against it, but he thought that Jews could do business with Christians because many Christians "were not devoted adherents of their religion but were simply following the customs of their ancestors" (Halbertal and Margalit's words on page 211).  The third approach was that of Rabbi Menahem Ha-Meiri, who maintained that Christians who were moral were not idolaters, for Rabbi Menahem Ha-Meiri thought that Tractate Avodah Zarah was talking about immoral nations when it referred to Gentile idolatry.

2.  On page 256, Halbertal and Margalit argue that the Bible prohibited Gentiles from worshiping idols only in the land of Israel, whereas it allowed them to do so outside of there.  They refer to such passages as II Kings 17 and Deuteronomy 4:19.  Halbertal and Margalit contend that the view that Gentile idolatry is forbidden under the Noachide commandments emerged in Talmudic times, and they cite Tosefta Tractate Avodah Zarah 8.4; Genesis Rabbah 16:16; and Babylonian Talmud Sanhedrin 56a.

I asked a few posts ago why Exodus 34:15 described Canaanite idolatry as harlotry, when Canaanites were not Israelites and thus were not in a covenant relationship with God that banned them from worshiping other gods.  Part of the answer may be that the Canaanites were worshiping in the holy land, where idolatry was prohibited.  I have another idea: perhaps some of the Canaanites were believed to be in covenant with God.  At Harvard Divinity School, one teaching assistant suggested that Ezekiel 16 depicts Sodom as having some sort of covenant with God.