Granted, there are many Israelis who would indeed volunteer and militarily, they are not in danger.
One of the ideas behind government is that certain situations are prisoner's dilemmas and that a central authority can make sure that the situation comes out equally for all. Rather than having people volunteer taxes, we write laws forcing people to pay them so that some person doesn't get to skip taxes yet get the benefit of the taxes being volunteered by others. Likewise, Israel is compelling their citizens to do military service. Heck, if you're an American male, you were compelled to register for the draft from 18-26 years of age and notify them if you moved residences - under the premise that such registration would make a future draft more equitable.
I'm somewhat just playing devil's advocate here since I tend to think that putting one's life in jeopardy is different from being compelled toward other ends. Would you object as strongly if you were compelled to serve the military, but could choose a non-life-endangering position? Say, IT support? What if the United States compelled people to do Americorps for a year or two after graduation? Does that qualify as slavery?
I guess I'm curious whether your objection is a more libertarian "any time the government compels its citizens, it's a form of slavery" or a life-ethic "when the government forces its citizens against their will to put their life in jeopardy, it's wrong."
This is not a rebuttal to the bulk of your post.
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.
---
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.
http://www.guardian.co.uk/world/2010/nov/22/germany-abolish-...
"The military was founded in 1955, and conscription – introduced two years later – has been seen as a necessary means to ensure the defence forces maintain a close relationship to civil society in order to prevent a repeat of the way in which the Nazi party was able to manipulate professional soldiers in the 1930s. But experts say it has prevented the military's modernisation."
Granted all go through basic training and then reserve training periodically after they finish their service, but that's because in a time of real existential danger, everyone fights.
If you are certified as combat-capable, and you are placed with a combat unit, you must go. If you refuse, you go to army jail. Army jail time does not count as service time, so when you get out of army jail, you still have a term of service to complete.
