Interestingly the case can be made that the military is not exempt from the 13th amendment, which only makes one single exception for prisoners. It's just that

Interestingly the case can be made that the military is not exempt from the 13th amendment, which only makes one single exception for prisoners. It's just that the courts have ruled consistently that OBVIOUSLY the military wasn't meant to be included in the ban against involuntary servitude. Obviously. Just like they have also ruled that mandatory Jury duty is not in violation of the 13th amendment either. Funny how the system protects and perpetuates itself. But with respect to your point, I am nearly 100% sure that it is not the case that employers can use financial penalties to enforce such a contract. Anything you are paid as wages is pretty much untouchable after it is paid out, unless it was paid in mistake or you intentionally damaged the company or something. The best the company can do is withhold potential future earnings or bonuses, or take back conditional non-wage payments like bonuses within a certain window of time. This is part of why golden parachutes exist. Your contract has very generous severance clauses which award you lots of money if you follow a certain procedures for leaving, which involves advance notice and such. Fail to follow that and your paycheck just stops the day you walk off. So there are incentives, but they can't go after your already earned wages, paid or still due to you.