In an attempt to shorten Bnei Yisroel's final journey to Eretz Yisroel, Moshe sends messengers to the King of Edom requesting permission to pass through Edom on the way to the Promised Land. The King of Edom refuses to grant permission and Bnei Yisroel are forced to take a more circuitous path. Thereafter, the Torah writes, "And Hashem spoke to Moshe and Aharon on Har Ha'har near the border of Edom, saying, 'Aharon shall be gathered to his people'" (Bamidbar 20, 23). Rashi explains that there is a reason the Torah emphasizes that this conversation took place near the border of Edom. Since they allied themselves with the wicked Eisav (Edom) they lost this righteous man (Aharon).
Rav Wolbe (Shiurei Chumash) notes, that all they wanted to do was simply pass through the Land of Edom undisturbed. If so, he asks, why did Hashem refer to this endeavor as an act of alliance with Edom and an interest in befriending Eisav? This question derives from the fact that we don't truly understand the danger of living among other nations. We are so used to living in galus, that we don't even realize to what an extent those around us influence our lives. We mimic their actions, copy their way of thinking and absorb their culture. Even merely speaking the language of the populace brings along with it certain negative influences. The most profound characteristics and ideologies of a nation are expressed through their language.
Bnei Yisroel merely requested permission to pass through the land of a foreign nation, and the Torah labels this attempt as an alliance with evil. The danger of such an action was so great that as a result they lost one of their greatest leaders.
We live in galus and there is nothing to do about it until Moshiach comes. However, what we could and should do is minimize the negative effect of the people among whom we live. Take a look around the house and see if there are things that are not proper for a Jewish home. If there are, why not dispose of them? Moreover, take a look around yourself and see if there are any hashkafos that have no place in a Jewish body!