Quoting “The Partial View”:
An acquaintance recounts how, during his tenure of study in Israel, he sat by Rav Elyashiv zt’l, as a ‘chayal’ from a hesder yeshiva, walked in and inquired as to the Kashrus of a Mezuzah at his military base.
Here’s the conversation: ‘L’mah ata mitkavain’ – what do you mean to infer, queried the Rav. ‘She’zeh dira ba’al korcho’ – that a domain in which an individual is coerced to abide in, is not a normative dwelling place, and is therefore absolved of Mitzvas Mezuzah? [See Tractate Yoma 10b]
“Zeh lo ba’al corchi, ani merutza la’asot tzavah!” – it’s not against my will, countered the soldier, I’m agreeable to army service!
“Zeh tzorich li’yot ba’al corchacha” – it should be against your will, said Rav Elyashiv.
Then he asked the zkan Haposkim the $64,000 question: “Lamah lo osim bnei yeshiva tzavah?” – and quoted the Rambam that it’s a mitzvah to defend the Yishuv in Eretz Yisrael against an enemy.
Rav Elyashiv answered: Yeshivaleit are not obligated to train, they’re only ‘mechuyav’ to fight – and then Tzavah won’t take them. Then he continued: And even if they are enjoined to train, you’re not mechuyav to put your life in the hands of Arik Sharon [Sar Bitachon at the time]. The Posek Hador provides clarity and perspective for this crucial issue.
Well, I don’t understand the first answer at all. And the second answer applies to all Jews, not just those studying Torah!