Daf YomiI - Yevamos 21 - FENCES AND SAFEGUARDS

Rabbis Safeguard Against Assimilation, As It Leads To Intermarriage
by Rabbi Frand

http://wap.torah.org/learning/ravfrand/5764/achareimos.html

Fences of Holiness

by Rabbi Zev Leff

http://www.shemayisrael.co.il/parsha/leff/archives/ach_kdsh.htm

A Fence Around the Torah – The Key to Yiras Shomayim

by Rabbi Zvi Sobolofsky

http://www.torahweb.org/torah/2006/parsha/rsob_acharei.html

Our Dual Relationship with the Secular World
by Rabbi Hershel Schachter

http://www.torahweb.org/torah/2005/parsha/rsch_vayishlach.html