Washington had no choice but conscription since the percentage of folks willing to voluntarily fight for their freedom seems to remain static until this day. 10-15% serve, the rest don't. Your problem is human nature and until you find a way to modify it, your brand of libertarianism is a pipe dream.
I agree completely. At least, I can see things from that point of view, and agree that you are speaking truth.
On the other hand, though, I'll point out that your problem is also human nature. The state you consider indispensible--as it probably is--always becomes the agent of oppression, because it's full of people, and people tend to oppress when they can. That's why I lean libertarian; of the two evils, I'd prefer the one in which I get left alone.
There's a third hand as well. Most anarcho-capitalists don't claim the world would be perfect without government; they only claim that it would be no worse. That's hard to know until you try it, but I must admit I find their arguments in this area persuasive. Except for the one problem you yourself raised: it will never be tried, because enough people aren't willing to try it anyway.
your brand of libertarianism is a pipe dream.
On the fourth hand, it will all be moot when Messiah comes.