States in Public or Private Capacity — States as “Nationals” — Distinction between State’s Exercise of Rights of Sovereignty and its Activities as Private Contractor — Article 304 of the Treaty of Versailles.

State Responsibility — Miscellaneous — Responsibility quasi ex contractu — Unjustified Enrichment.

Arbitration — Cause of Action Invoked by Litigant — Substitution of Different Cause of Action by Arbitral Tribunal.

Arbitration — Jurisdiction — Litispendance — Mixed Arbitral Tribunal and Reparation Commission.

Occupation of Enemy Territory — Respect of Private Property — Article 53 of Hague Convention of 1907 — Right to Seize Means of Transportation — Initial and Supplementary War Measures — Negotiorum gestio — Occupying Power as Carrier of Passengers and Goods — Quasi-Contracts — Jurisdiction of Mixed Arbitral Tribunals — Plea of Litispendance — Conflict of Jurisdiction between Mixed Arbitral Tribunal and Reparation Commission — Possible Denial of Justice.