Treaties — Interpretation of — Principles and rules of — Principle of effectiveness — Intention of parties — Treaty of Friendship, Commerce and Navigation between United States and Greece — Effect upon state law imposing condition of reciprocity upon right of alien to inherit — The law of the United States of America.

Aliens — Treatment of — Right of non-resident alien to inherit property — Conditioned by state statute upon reciprocal right of inheritance of United States citizens in alien's country — Conflict between statute and treaty between United States and country of alien — Treaty of Friendship, Commerce and Navigation between United States and Greece, 1951 — Interpretation of — The law of the United States of America.