State immunity — Jurisdictional immunity — Commercial activity exception — State corporation — Action between two foreign corporations — Whether action having sufficient nexus with the United States — Requirement that commercial activity having direct effect in United States — Whether economic loss resulting from failure to honour financial obligation under contract constituting direct effect in the United States — Payment of funds into New York bank account of foreign bank for purposes of satisfying bank guarantee — Whether constituting direct effect in the United States — United States Foreign Sovereign Immunities Act 1976 — The law of the United States