States as international persons — In general — Sovereignty and independence — Conduct of foreign relations — Conclusiveness of statements of the Executive — Agreement on reciprocal exemption of diplomatic property from real estate taxes, 1979, between German Democratic Republic and United States — Interpretation — Weight to be given to Department of State views — The law of the United States

Jurisdiction — In general — Territorial — Exemptions from and restrictions upon territorial jurisdiction — Foreign States — Sovereign immunity — Exemption of diplomatic property from taxation — Agreement on Reciprocal Exemption of Diplomatic Property from Real Estate Taxes, 1979, between the German Democratic Republic and the United States — Foreign Sovereign Immunities Act 1976, Sections 1609 and 1610 — Whether commercial acquisition of property necessarily implies use of property as commercial activity — The law of the United States

Treaties — Conclusion and operation of — Operation and enforcement — Necessity for municipal legislation — Agreement on reciprocal exemption of diplomatic property from real estate taxes between German Democratic Republic and United States, 1979 — Whether Agreement part of Law of the Land — Whether United States grant of immunity takes precedence over local denial of immunity — The law of the United States

Diplomatic and consular intercourse and privileges — Permanent diplomatic envoys — Privileges and immunities of — Diplomatic premises — Immunity from local taxation of property owned by German Democratic Republic — Agreement on reciprocal exemption of diplomatic property from real estate taxes, 1979, between the German Democratic Republic and the United States of America — Whether President had authority to enter into Agreement — Diplomatic Relations Act 1978 — Whether immunities primarily serve individuals or foreign sovereign — Whether United States grant of immunity takes precedence over county's denial of immunity — Interpretation of 1979 Agreement — Weight to be given to Department of State views — Whether commercial acquisition of property necessarily implies use of property as commercial activity — Sovereign Immunities Act 1976, sections 1609 and 1610 — The law of the United States