From R. Asher Bush's weekly parashah e-mail:
A few years ago when asking Rav Aharon Lichtenstein about a particularly sensitive situation regarding such a matter [Jew/Gentile relations - GS] his response to me was, “What do you think Avraham Avinu would have done?!” This is a question that is not asked often enough, as it is only through a life based on his example that the world around us can come to say נשיא אלקים אתה בתוכינו [“You are a prince of God among us” - Gen. 23:6].