Being employed producing the hardware for the defense of our country need not be voluntary. The government could send us draft notices ordering us to report for work at General Dynamics' Texas track-vehicle facility at $400 a month. If the government did this, would you call it a draft or slave labor? Not to worry, the Defense Department offers attractive contracts to firms like McDonnell Douglas and General Dynamics, and they in turn offer attractive wages to employees, and thus, volunteerism gets the right number of workers to make the right number of jets and tanks.
The Defense Department might argue that a draft is needed because it would be too expensive to pay market wages to get the desired number of soldiers. It would be right so far as the military budget is concerned but wrong when it comes to military's true cost to the nation. The true cost of a soldier in the army is the value of what he could have produced, and society must sacrifice, were he not in the army -- what economists call ?opportunity cost.? Even if the military paid the soldier nothing, the nation must forgo what the soldier could have produced were he not in the military.
National defense is an important government function; for rational decision-making, we mustn't permit concealment of its cost through measures like the draft.