It's highly unlikely that the US will return to conscription, particularly for anything less than WWIII. The problem with draftees is that they tend to be less effective soldiers (since they didn't sign up to be a soldier), and the terms of conscription are too short to effectively train them--if someone is in the army for a year, and it takes 6 months to train them, you're spending a lot of money to little effect.

The main value of undertrained infantry soldiers is to provide literal boots on the ground to bolster the mass of a fighting force, but modern warfare tactics have generally lessened the effectiveness of this kind of mass: an integrated combined arms team can easily steamroll a fortified infantry line, as was shown quite clearly in the First Gulf War.