I served in the AF for 28 years, from 1975 to 2003, and mandatory service or the draft isn't what this country or the military needs. What you get with both is a lot of unfit, unqualified, overweight, poorly educated people, and people who wouldn't want to be in the military straining the ability of the military to perform its missions.
These people will take up more time requiring training, retraining, supervision, etc.., than the officers and NCOs have time to devote. Additionally, the monetary costs of this would be astronomical considering the military's infrastructure isn't built of this. Here are some of the problems I see:
The pay for an E-1 is currently $2,407.20 per month ($28,886.40 per year) which means just the pay for the military would add billions to the defense budget.
Where do you house all these people? Junior enlisted personnel are required to live, in most instances, on-base unless they are married. Even paying them a housing allowance to live off-base would be huge and it would be even higher for married personnel who get a larger housing allowance.
How much will it cost to feed them? Junior enlisted, who make up the bulk of the military, would have to eat in the dinning hall or receive a subsistence allowance for them to buy their own food. If they're married, they receive an extra amount to help cover the food costs for their family.
The military healthcare system is designed to handle a relatively healthy population since the military doesn't take those with serious or long-term health issues. Adding these people the system would overload the system and degrade it putting readiness in danger.
After their service, they would be eligible for VA care if they had a service connected disability furthering straining that system.
There are other problems but IMO, those are the biggest ones.
While is seems like a good idea to people like Palantir, take it from someone who made the military a career having mandatory service or the draft isn't needed in peacetime. Even in wartime, a draft requires time to process, train, and deploy troops and in today's modern area of warfare having large numbers of troops doesn't equate to victory or success on the battlefield. Ukraine has proved this with Russia.
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