The greater idea would be that free people should not be forced to go and wage aggressive war. If a political entity decides in favor of war and there is conscription, individuals can't legally refuse if they disagree. Sure, aggressive wars can be waged with professional armies, but then at least there is the possibility of opting out.

In the case of defensive war, there are two options: take refuge or take up arms. Sometimes, the refugee option is better. If you're a married man, your first responsibility should be toward the safety of your family. If that means running away, that is indeed the better option.

Learning to defend oneself and one's family should be a primary responsibility. But I'm not sure the army is the only means to achieve that.

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As an aside, in a country with conscription there would be no civilians. If all able-bodied men/women are expected to serve in the military, they are fair game according to the rules of war. Conscription is one of the things that makes total war possible. Without conscripts, the war machine will eventually run out of money. With conscripts, the state can wage war up to the point of self-destruction.