There are many types of impurity. In the Torah reading on Shabbat, we learned about the impurity (tumah) of certain creatures, like worms and lobsters and pigs and vultures, which makes them off limits when it comes to food. We also learned about the parah adumah, the red heifer, and the impurity of death. In the Haftorah, we learned about the impurity that results from living in the Diaspora and G-d’s promise to heal us from this spiritual uncleanliness by bringing us back to Eretz Yisrael and putting us through a gradual, step-by-step spiritual overhaul (Ezekiel, 36:16-38).
Outside of Israel, the land of the nations is impure and the air is impure as well (see Tractate Shabbat 14B). Recently, this has been made clearer with the nuclear plant disaster in Japan and the cloud of radiation that is spreading over the Diaspora, but even without this, there is a spiritual radioactivity that envelopes the Diaspora, and this impure atmosphere has a devastating effect on the Jews who chose to live there.
Rabbi Kook writes: “The poisonous air of the Diaspora sustains the life of the nations that live there, providing them with what they need, but it cannot provide even a millimeter of the unique idealism vital to the Jewish People. The air there pollutes the Jewish heart and brain, causing weakness and clouded thought” (Ikve Hatzone, pg.114).
Elsewhere, Rabbi Kook writes: “Revelations of holiness, on whatever level, are clean in Eretz Yisrael, while outside the Land of Israel, they are mixed with abundant dross and impure husks” (Orot, 1:4).
The air in the exile causes mental impurity and dullness. It is filled with the polluted influence of the strange and foreign cultures of the gentiles, which cloud the spiritual vitality and national idealism of the Jewish People. The clear thought processes of the Jewish People, and the spirit of true national Israeli life, can only be found in the pure holy air of the Land of Israel.
The Gaon of Vilna, certainly one of the most outstanding Torah giants of the last 500 years, compared the Diaspora to a grave, in that “the national body of the Jewish Nation is destroyed in the exile, our flesh is eaten away by the worms of the foreign cultures which are omnipresent there, which devour us physically and spiritually, until even the bones of the nation, the Torah scholars, become rotted away” (Likutei HaGra, at the end of his commentary to Safra D’Ziniuta).
For example, the spiritual pollution and dullness of thought in the Diaspora finds expression in the belief that life in the exile is perfectly OK and even enjoyable. When you explain to Diasporians that the very opposite is the case, that Jewish life in the Diaspora is polluted, they have no idea what you are talking about. They simple can’t fathom what you are saying because of the cloud that has settled over their hearts and their brains. Just like with radiation, they can’t see it. But a Geiger counter of a soul like Rabbi Kook’s, and the soul of every Jew whose heart pulses with a love for Eretz Yisrael, can actually feel the spiritual pollution of the Diaspora when he’s there.
"What is he talking about? The air couldn't be cleaner!"
What’s the solution? The Prophet Ezekiel tells us:
“For I will take you from amongst the nations, and gather you out of all countries, and will bring you into your own Land. Then I will sprinkle clean water upon you, and you shall be clean; from all of your uncleannesses and from all your idols, I will cleanse you….” (Ezekiel, 36:24-25).
G-d has given us El Al Airlines and money to buy a ticket. He has built up the Land into a thriving, modern country, a world leader in all fields. Why live in a grave in Japan, New York, or Toronto when you can live in the place where G-d wants us to be?