I don't consider a doctor any different than any other employee when it comes to contractual obligations. Signing a contract does not mean you cannot choose to break it, it just means that there will be repurcussions should the contract be broken, usually they are financial- and certainly it could impact future opportunities, but no matter what the contract if an employee decides today they will not work another day then they are free to go.
It might not be an ethical decision on the part of the doctor but how exactly would one force a doctor to stay in a job they've decided to leave?
Restrain them, consider some type of criminal charges? These things don't seem to me a way to avoid the loss of medical professionals.
I'm not suggesting any doctor be forced to work against their will. I'm saying that doctors are, like other professionals, required to finish their contract, change it legally, or forfiet whatever is forfieted according to the contract.
Doctors have the added responsibility that they can not just walk out whenever they please - they can't just leave a patient on the surgical table without a) finding a replacement or b) finishing the surgery. This isn't any different from a teacher, who can't just walk away during the middle of a field trip while being responsible for 30 minors.
If a doctor chooses to walk out of the job with no notice they are free to do so. However, they will have to deal with their legal obligations as per their contract.
Nowhere did I suggest that doctors should be forced to work against their will. However, I did suggest that there are better ways of dealing with understaffing, such as contacting their professional organization, discussing the problem with the hospital execs, etc.
Being a doctor comes with rights, but also responsibilities. A doctor must give adquate notice; a doctor can't just walk out while performing surgery. Being a doctor is different than working at Wal-Mart in that if a doctor decides to walk out in the middle of a shift they may in fact be letting a critically-ill patient die.
Let me make this clear: I am not advocating that a doctor stay in a job they do not want to stay in. However, I am saying that they have a responsibility to not just walk out while treating patients.
More to that, if a doctor knows their hospital is understaffed, they could go to their professional organization or even to the hospital execs, explain the problem, and give the ultimatum that they will break the contract unless the hospital hires the necessary personal.
And of course, there are laws dealing with doctor's legal responsibilities and rights. Which, frankly, makes this discussion pretty hypothetical.