States — Conduct of foreign relations — Export ban on sale of nuclear equipment by private company to foreign State entity — Whether justiciable by French courts — Whether Executive decision prohibiting export constituting an acte de gouvernement — Whether severable from conduct of foreign relations by French Government

State responsibility — Acts and omissions of State organs — Export of nuclear materials — Refusal of ministerial authorization resulting in cancellation of contract — Whether State liable to pay compensation to exporter

Economics, trade and finance — Export ban — Sale of nuclear equipment by private company to foreign State entity — Refusal of Executive authorization — Claim for compensation against French State — Whether municipal courts having jurisdiction — The law of France