I don't think universal service would end wars, quite the opposite. It would give moral clarity to our national position. A congress of 535 members who once wore the uniform would understand their freedoms just a wee bit better, and cherish and defend freedoms throughout the world.
It is a volunteer army. However, nobody that I served with was from even the upper middle class let alone rich, in the enlisted class. It is a dividing line. It is not a conservative or liberal thing. Rich folks don't serve.
The word chickenhawk is thrown around quite a bit, but it can be useful in the sense that, when somebody isn't willing to die for a cause, but they are willing to let your kids go instead, it does give you a moment to reflect on the urgency of the cause.