Universal Postal Union, [613]

Universal Telegraph Union, [614]

Usage, international, in contradistinction to international custom, [22]

Usurper, 427

Utrecht, Peace of, [63], [278], [583]

V

Vaderland, case of the, [357]

Vassal States, [140]

cannot be parties to offensive alliances, [142], [597]

cannot cede territory without consent of suzerain, [286]