Mdd,
Please give me the citation within Megilas Ta’anis and especially the source for Tzidikiyahu.
Please explain what the proper pshat in the Gemorah of the Sanhedrin leaving the Lishkas HaGozis.
Being drafted is part of the public sphere and therefore can be made mandatory. But to reiterate, I am talking about drafting not actually serving, which cannot be forced. Similarly, it would be okay to have a core curriculum that included Tanach and Talmud and if a school refused to provide these subjects it would be fined and eventually closed.