History has shown that a smaller, willing military is far more effective than a larger, forced military. The U.S. Military won't revert to drafting people unless it is absolutely necessary. The selective service was put into action, and remains in place, to combat conflict that is considered to be on a global scale. WW 1 & 2 were good examples of the necessity of a draft, but the Vietnam campaign showed how drafting unwilling soldiers can have a negative effect.