I definately believe in living up to one's obligations. But, I just love to play the devil's advocate too...So here I go.
If you enter into a good-faith agreement with another party, but that agreement was made on false premises then I think that you have a legitimate and honorable right to stand up for yourself. In fact, I think that you'd be fool if you didn't.
I'll use a simple analogy. Let's say someone sold you a car after telling you that it had 10,000 miles and was only driven to church on Sundays by his grandmother. You discover that the car was actually a stolen vehicle recovery that had a salvage title which greatly diminished the resale value. You were duped! Now, would you just sit back and take it because you wanted to live up to your end of the bargain or would you introduce the dude's backside to the toe of your shoe?
I can't think of a better analogy than used car salesmen and recruiters. In my experience, I can honestly say that I have never met a recruiter that didn't lie and/or try persuading an applicant into lying. Because of my long affiliation with the military, at least I knew they were lying. If a newbie gets blindsided by a used car salesman, I don't at all feel that they have an unwavering duty to honor their agreement if it was made under false pretenses.
It's called full disclosure. If a contract is made with deceptive practices, that contract can be voided. My point is that recruits shouldn't have to be deceived. If they're unhappy where they are and how they got there, they are much less likely to be a happy/productive team member. Tell them the truth and let them make informed decisions. Let them be proud of their service instead of resenting it.
Of course, my opinion on this subject is tempered by my experiences. That being said, I have enjoyed most of the time that I've had in the military...active duty, national guard, enlisted, commissioned, HPSP, flight surgery, two trips to Saudi, lots of shorter trips elsewhere...I've been around the block. And with the exception of HPSP, I'd do it all again.
To tell you the truth, I have always thought that a couple of years as an enlisted person should be mandatory in the U.S. I loved Army basic training and I think that there are a lot of young adults that could use some discipline these days.