Since I am involved in designing and fielding parts of this system, I am qualified to speak on the subject.
Consider the US Army's Future Combat System as but a single example of what I am referring to. I can sight numerous others but this one will do. (For actual information on FCS, search on-line, or watch The History Channel's Future Weapons Series.)
FCS is a system of systems linked together by a secure, wireless, self-reforming, communications network. This ties together manned and un-manned sensors, manned and un-manned weapons delivery platforms, Army commanders (Brigade to platoon), other US services, non-US allied forces, and the boots on the ground. Eventually this will go down to the individual soldier via the Land Warrior system.
FCS is a great force multiplier. In some cases it can make a single squad equal to or superior to a full company of American WWII soldiers.
The motivation, intelligence, and training necessary to understand and use this system to full advantage is best obtained through a carefully screened, and trained volunteer force. This is not an AK-47. You can not effectively use this with 30 minutes or 30 days training.
The enemy has two great strengths, a large supply of willing, all be it, generally untrained fighters and a cadre of willing accomplices within the American media and politicians trying to undermine the will of the American public to prosecute this war to victory. (Note: I am not claiming that Ron Paul or any other anti-war person is deliberately aiding the enemy. But if they were, how would their actions be any different.)
The enemy has two great weaknesses, general lack of education, and far lower technology level the weapons available to them.
We have chosen to pit our strength against the enemy's weakness (Control of information flows and superior weapons technology). A draft might give us many more troops but then it would put our weakness against his strength. Furthermore, even with a draft and generally unlimited resources, it might still be close to two years to effectively field cohesive units ready to fight using the Army's combat doctrine. A large number of draftees would still only be suitable for stateside guard duty and hauling trash. It would be better to but them on our southern border.
Hope this answers your question. I can write a lot more.
Garde la Foi, mes amis! Nous nous sommes les sauveurs de la République! Maintenant et Toujours!
(Keep the Faith, my friends! We are the saviors of the Republic! Now and Forever!)
LonePalm, le Républicain du verre cassé (The Broken Glass Republican)