Orthodox Jews have taken on more and more responsible government positions and have been trusted with clearances to see highly sensitive classified materials. Many years ago I had such a job. It never happened to me, but I can envision a situation where an unpublicized national security incident has resulted in the Jewish White House or Defense Department worker to be called into the office on Shabbos. He/she goes to his rav to ask whether he can go in. The rav says he needs to know the nature of the emergency. Assume the rabbi does not have security clearances.
Can the rav give a heter simply by relying on the assurance of the congregant that the issue involves a classified matter that is of national importance, potentially life-and-death, and requires his/her personal attention and that he can't tell him anything more?
If the rav insists on more information, does he have a halachic responsibility to not disclose the confidences of his congregant, similar to the requirement of a Catholic priest not to devulge confessional information (I say this because the parrishoner-priest confessional is a recognized privilege in courts of law)?
Would American law permit or prohibit any disclosure to the rabbi? A retired Army chaplain told me he thinks that the congregant would not be held responsible, but I've been unable to find a source in statutes or in case law. Moreover, I've seen cases where someone lost their clearances because, during a polygraph examination, he admitted to revealing information to his wife -- where there is also a legal privilege recognized in courts.