Diplomatic relations — Immunity — Special envoy — Sending State designating diplomatic official as special envoy — Whether entitled to claim diplomatic status in receving State — Whether receiving State having discretion to classify special envoy as Head of Mission — Waiver — Participation in legal proceedings — Initiation of legal action prior to award of diplomatic status — Whether constituting waiver of immunity — Assertion of legal claim after award of diplomatic status — Whether constituting waiver of immunity — Vienna Convention on Diplomatic Relations, 1961, Article 14

Relationship of international law and municipal law — Conduct of foreign relations — Certification by Executive that foreign national entitled to claim diplomatic status — Whether binding on the courts — The law of the United States