CITE: 22CFR9 - The United States Code of Federal Regulations

    Sec. 9.3 Responsibility for safeguarding classified information

    (a) Primary. The specific responsibility for the maintenance of
    the security of classified information rests with each person
    having knowledge or physical custody thereof, no matter how
    obtained.
  
  

CITE: The Vienna Convention on Diplomatic Relations
and Optional Protocols - Done at Vienna, on 18 April 1961

    Article 41

    1. Without prejudice to their privileges and immunities,
    it is the duty of all persons enjoying such privileges and
    immunities to respect the laws and regulations of the
    receiving State. They also have a duty not to interfere in
    the internal affairs of that State.
  
  

CITE: 28USC--App.501 - The Diplomatic Relations Act

"...Article V as submitted to Congress contained 13 rules. Nine of
those rules defined specific nonconstitutional privileges which the
Federal courts must recognize (i.e., required reports, lawyer-client,
psychotherapist-patient, husband-wife, communications to clergymen,
political vote, trade secrets, secrets of state and other official
information, and identity of informer)..."
  

    Rule 501. General Rule

    Except as otherwise required by the Constitution of the United
    States or provided by Act of Congress or in rules prescribed by the
    Supreme Court pursuant to statutory authority, the privilege of a
    witness, person, government, State, or political subdivision thereof
    shall be governed by the principles of the common law as they may
    be interpreted by the courts of the United States in the light of
    reason and experience. However, in civil actions and proceedings,
    with respect to an element of a claim or defense as to which State
    law supplies the rule of decision, the privilege of a witness, person,
    government, State, or political subdivision thereof shall be
    determined in accordance with State law.

  "...that a Federally developed common law based on modern
   reason and experience shall apply except where the State
   nature of the issues renders deference to State privilege law
   the wiser course..."

"...If the rule proposed here results in two conflicting bodies of
privilege law applying to the same piece of evidence in the same case,
it is contemplated that the rule favoring reception of the evidence
should be applied. This policy is based on the present rule 43(a) of the
Federal Rules of Civil Procedure which provides: In any case, the
statute or rule which favors the reception of the evidence governs and
the evidence shall be presented according to the most convenient
method prescribed in any of the statutes or rules to which reference
is herein made..."