The decline of conscription

Ilya Somin explains:

Many people resist the comparison between conscription and other forms of forced labor because they see military service as providing a great good that is essential to our society. But military service is far from unique in that regard. Historically, slaves and forced laborers often performed work that was vital to the social order. The entire economy of the antebellum South depended on crops produced by slaves. So too with ancient Rome, Russia in the era of serfdom, and so on. 

The key point to realize is that this work, however noble and necessary, can be performed by free laborers. Thus, the use of forced labor to carry it out is still unjust. The same goes for military service. Both the United States and other liberal democracies can field more than adequate military forces without conscription. Indeed, they can create better armies without it than with it.