Slightly different, that is an operative agreeing to be an operative with up front knowledge of what it entails. So the person lying has agreed to lie before being given the information or a mission. If you know a case where a person has been prosecuted for not lying rather then breaking an agreement I would still be interested.

I am not sure what I think about your scenario off the top of my head but I do consider it different.

You could choose to take a job where you are required to lie, but no-one can force you to take such a job.

The Military Selective Service Act disagrees with you.

You couldn't be conscripted in private and compelled to lie.