Rabbi Shlomo Aviner on the Orthodox Union Network http://www.ou.org/shabbat_shalom/article/aviner_parashat_vayechi_5768/
From a talk given after lunch at the yeshiva -Q: It is a mitzvah to be drafted into Tzahal?
A: Absolutely. It is a mitzvah for three reasons – just as everything in the army is in threes:
1. Pikuach Nefesh - The army protects the lives of millions of Jews; we have many enemies. Saving a life overrides just about every mitzvah in the Torah except the most severe ones.
2. Conquering the Land – The army safeguards the Land of Israel. There is a mitzvah to conquer the Land and then to hold onto to the Land. At the end of the book "The Kuzari," the King of Kuzar asks, is the reason you do not make aliyah to Israel is that it is dangerous? The Jewish spokeman answers that it is not dangerous, and even if it were dangerous, it is not more dangerous than an obligatory war which we are also required to fight.
3. Sanctification of Hashem's Name - When the Nation of Israel is low, pitiful and oppressed; it is a desecration of Hashem's Name. When we are strong and settled in our Land it is a sanctification of Hashem's Name. Rav Nisenbaum – who was a major Zionist – once said: What is sanctification of Hashem's Name? It is not when it is written on a Jew's tombstone that he was murdered sanctifying Hashem's Name.
Some say that the army is no good. It does not protect modesty, it expels Jews, etc… Don't exaggerate! It is true that there are immodest things which occur, but it is not completely immodest. It is true that it was used to expel Jews, but do not say that it is the "Israel Expulsion Army." We struggle against these things, but just as a person is judged on the majority of his acts, so is an army. "There is no righteous person in the world who does good and does not sin” (Kohelet 7:20). The army is judged on the majority of its acts. Yes, there are problems, but what do you suggest? No army. If we did not have an army, we would have no immodesty problems – all Jews would be dead. If we did not have an army, there would be no expulsions, because all Jews would be dead. On the whole the army is good, and it is an army of Hashem.
Blogmaster's comments: The next time you see a member of the IDF and you have the opportunity... tell that soldier how much he (or she) is appreciated. Although most of us feel that way, we seldom (have the opportunity) say it.