Alliance

The union or connection of two persons or families by marriage, which is also called affinity. This is derived from the Latin preposition ad and ligare, to bind.

International Law. A contract, treaty, or league between two sovereigns or states, made to insure their safety and common defence.

Alliances made for warlike purposes are divided in general into defensive and offensive; in the former the nation only engages to defend her ally in case he be attacked; in the latter she unites with him for the purpose of making an attack, or jointly waging the war against another nation. Some alliances are both offensive and defensive; and there seldom is an offensive alliance which is not also defensive.