The result would be that the draftees would still have the option of a career path if they chose to follow it. Your response was a straw man, as I didn't say that there would be no professional military.
Now, in WWII, there was a draft. The nation was on a war footing, nearly every American supported the war, sacrificed for the war, did what they could to win the war. The result was that the war was won in about three years. In Vietnam, there was a draft. Only a few supported the war, found the war really necessary, sacrificed for the war. As a result, the war dragged on for a total of 21 years, and we lost.
In the current wars, only the military has sacrificed anything for the wars, the average American has taken no part at all in the wars, and they have dragged on now for a decade.
The point of all that is that we should never go to war unless the entire nation is behind it, willing to sacrifice for it, willing to go and fight, and to do whatever it takes to win it.
WWII was necessary, but neither Vietnam, nor Iraq, nor Afganistan were.