The individual in international law — Aliens — Expulsion of — Right of expulsion — Convention Relating to the Status of Refugees, 1951 — Article 32 — Duty of Contracting States not to expel refugees lawfully in their territory save on grounds of public order or national security — Chinese nationals resident in Hong Kong entering United States as non-immigrant crewmen — Remaining in United States beyond authorized period — Whether lawfully in the territory — Whether refugees unlawfully in the territory of a Contracting State after period of residence in third country are protected by Article 31(2) — The law of the United States