State immunity — Jurisdictional immunity — Action against foreign State — Procedure — Service of writ — Whether practicable to transmit writ through Ministry of Foreign Affairs — Conditions for service of writ by publication — Identity of defendant — Whether ambassador of foreign State a proper defendant — Action against the Union of Soviet Socialist Republics regarding Chernobyl accident

Diplomatic relations — Immunity — Diplomat — Ambassador — Action against foreign State — Whether ambassador a proper defendant

Jurisdiction — Territorial — Tort committed outside jurisdiction — Effects within jurisdiction — Burden of proof

Environment — Action against State regarding environmental damage — Chernobyl nuclear accident — The law of the Federal Republic of Germany