States — Definition of State — Attributes of Statehood — Territory — Population — Government — Capacity to enter into foreign relations — Palestine Liberation Organization (“PLO”) — Whether possessing attributes of Statehood — Significance of declaration of Statehood by PLO — Significance of recognition by other States

State immunity — Jurisdictional immunity — Entitlement to immunity — PLO — Whether entitled to State immunity — Decision turning on whether PLO constituting State under international law — Foreign Sovereign Immunities Act 1976

Recognition — States — Effect of recognition — Effects in law of recognizing State — PLO — Non-recognition by the United States — Whether PLO immune from jurisdiction of United States courts due to non-recognition

Territory — State territory — Nature of territorial sovereignty — Headquarters of international organization situated within territory of State — Relationship between organization and territorial sovereign — United Nations Headquarters — Whether under sovereignty of United States — Agreement between United States and United Nations regarding the Headquarters of the United Nations, 1947

Relationship of international law and municipal law — Conduct of foreign relations — Justiciability of foreign relations questions — Political question doctrine — Criteria for determining application of — Terrorism — PLO — Action in tort brought by United States national alleging involvement of PLO in act of terrorism committed abroad — Whether justiciable

International organizations — Immunity — United Nations — Representatives accredited to international organization — Immunity from jurisdiction — Whether extending to Permanent Observers — United Nations-United States Headquarters Agreement, 1947 — Whether Headquarters Agreement conferring immunity from jurisdiction on PLO mission

Jurisdiction — Personal jurisdiction — Tort committed abroad by foreign entity — Jurisdictional requirement of forum State that foreign entity having sufficient presence within State — “Doing business” test — Action in tort brought against PLO with regard to commission of terrorist offences abroad — PLO Observer Mission at the United Nations — Whether activities undertaken by Observer Mission constituting basis for jurisdiction under “doing business” test — New York Long-Arm Statute — The law of the United States