I believe I can address your economic concerns GS.
According to the OMB, on Table 3.2, of the entire (050) Military Budget, Military Personnel accounts for $137,401,000,000 of their $607,263,000,000 budget. Now, given that between Active and Reserves, there are approx. 3 Million serving today, and using the US Census Bureau numbers, by extrapolating from the age group of 15-19 year olds, to get only 18 year olds, we arrive at 4,550,856. Ignoring for the moment that a small percentage of them will not be fit for military service, that would increase our military to a total of 7.5 million, that would mean the Military Personnel part of the budget would be increased to $300,000,000,000 per year since entering Soldiers, Sailors, Airmen, and Marines receive the lowest pay, thereby increasing the total National Defense budget to $769,862,000,000, a total increase of only 25%. If we change the enlisment time from the current 4 or 6 year enlistments to only 2 year enlistments for 1st tour military personnel, we would actually see a DECREASE in the Personnel budget, since many 1st tour troops find very quickly that making a career out of the military really isn't for them, and they would be leaving, rather than being forced to stay 2 to 3 times as long as they would wish.
Now, I know that you're looking to "downsize" the overall budget as much as possible, and generally I agree with you, however in this case, I believe that the benefits received from militry service far outweight the costs, unlike the "social programs" that we have today. By instilling discipline, team work, and "mission focus" on our young people, something that is sorely missing in todays society, that additional expendature would be far offset by the inceased productivity of those young people.
If we're going to cut anything, I believe we should start with Social Security, Medicare, Medicaid, Welfare, Food Stamps, WIC, Section 8, HUD, and all of those other programs that currently make up over 60% of our annual Federal Budget, along with every program, Department, and Agency that is not specifically allowed for under Article 1 Section 8 of the Constitution.