"Esav Hates Yaakov"
It is a 'Halachah l'Moshe MiSinai,' literally down straight from Sinai, that Esav hates Yaakov, generally rendered as "at the end of the day - Goyim deep-down, hate Jews, period. It can't be argued about since it's deeper than reason with Goyim - it's a stated fact, down from Sinai". First off, I need to add links regarding what "Halachah l'Moshe MiSinai" has been understood to mean - among them a statement from R. Soloveitchik that it definitely does not necessarily mean something stated at Sinai passed down from Moshe Rabbenu - along with similar discussion form Rabbinic literature. But that later; here are some links I hope to summarize and repost as links, but I'd like to just give the links until later this week.
http://www.cross-currents.com/archives/2006/09/05/is-antisemitism-universal/
http://haemtza.blogspot.com/2006/07/jew-and-jew-jew-and-non-jew.html
http://dovbear.blogspot.com/2007/11/esav-sonei-leyakov.html
http://haemtza.blogspot.com/2006/07/halacha-he-esav-sonei-lyaakov.html
http://www.torahmitzion.org/eng/resources/show.asp?id=113