Nationality — Individuals — Change of nationality — Loss of former nationality — Defection — Whether leading to automatic forfeiture of nationality — Cuba — Acquisition of nationality — United States nationality — Cuban defector given asylum in United States of America — Marrying United States citizen — Formal grant of nationality in 1999 — Whether becoming United States citizen at earlier date — Whether stateless at some point — Proof of nationality — International Olympic Committee — Rule that person who had represented one State could not represent another until three years after change of nationality

International tribunals — Arbitration — Court of Arbitration for Sport — Evidence — Proof of nationality under national law — Whether letter from Ambassador conclusive