universal conscription is similar to how people are forced to go to school in most societies

I recognize the difference you are making, but this seems like huge a stretch. Children's lack of knowledge requires some degree of restriction on autonomy at least to a certain age, in the interest of preparing them for life. Personally I think school mandates are excessive in most countries, but it is still very different from a mandatory activity for adults. Moreover, the military represents a far greater risk of personal harm. As to the idea that it is self-organizing, the degree to which that is true rests heavily on the democracy question.