Yekke, you can find his opinion in Bet HaBechira on href=”http://www.hebrewbooks.org/pdfpager.aspx?req=40773&st=&pgnum=325&hilite=”>Baba Kama 113b .
This was also the opinion of Rav Kook (Iggeret 89), Maharatz Chajes (Tifferet l’Yisrael, Rav Shimshon Raphael Hirsch (<Collected ritings v. 7 “Talmudic Judaism and Society”, Rav David Tzvi Hoffman (Fundamentals of Judaism edited by Jacob Breuer ch. 8 , Rav Yaakov Emden (on Pirkei Avot 4:13), Rav Aharon Soloveichik ( “Logic of the Heart, Logic of the Mind pages 139, 151) and Rav Nahum Rabinovich, and Rav Lichtenstein in the name of Rav Joseph Soloveichik (Laws of Medical Treatment on Shabbat by Rabbi Dov Karrol, who all say that gentiles who have an orderly society are considered gerim toshavim. RAS adds that the mitzva of קידוש השם only applies where there is an ethical imperative to so act (קדש עצמך במותר לך) – we do many things despite the fact that the other nations dislike them.