We used a draft for WWII.
I was drafted and served honorably during Vietnam. I worked in military personnel management, and do NOT recall draftees being any more or less difficult, than volunteer enlistees.
It appears the relatively small size of our military is resulting in extensions, for regulars and reserves. This may, in turn, be making service less attractive.
Or maybe we need to pay the military people at a high enough rate, that the supply is high enough to avoid the draft?
Now we get into cost/benefit analysis. At what point does a draft become cheaper? At what point does the military become a gang of mercenaries? At what point do we decide it's cheaper to hire soldiers from India or other impovershed nations?
How high would you like to go? Let's take for a moment a 20 year old Army Private, E-3, married, in Iraq with a paratroop unit. His base pay is $1641, his housing allowance is $504, he gets $250 per month separation pay and $150 a month in jump pay. Total is $2545 per month or over $30,000 per year. Not bad for a 20 or 21 year old out of high school.
God knows my point is not to begrudge the troops the pay that they get. They earn every dime and more. But money is not the answer. I would be amazed if you can find more than a handful that enlisted for the money, and most military people I served with would be highly insulted if people thought that they were in it for the bucks. People join for reasons not remotely related to salary, and thinking that if you can only increase the salaries to a certain level and that'll get you all the troops you need will probably do nothing but get you people enlisting for the wrong reasons.