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.
But ...
You are confusing cause and effect. Israel and South Korea, have conscription because of war. Both would rather live in peace but both are technically at war and have been for decades. Not to be confused with conscription during Vietnam which was a foreign war.
> As an aside, in a country with conscription there would be no civilians
It depends on the country, but my understanding is that you can choose to relinquish your citizenship you no longer have to serve. Of course you would need to seek refugee status in a sympathetic country.
You cannot always have the benefits of citizenship without paying a cost.