Alliances

Alliances are diplomatic or military arrangements made between nation-states, either formally or informally, to increase cooperation for security from outside aggression. Alliance building has maintained a large presence in the history of sovereign states from ancient history, a prime example being the Delian League of ancient Greece, to the modern period, the North Atlantic Treaty Organization (NATO) being the best modern example of an alliance system at work. Alliances were traditionally viewed by policymakers as essential tools to maintain a balance of power between competing states and are still seen in this light in today’s global society. This entry describes some basic characteristics of alliances and their historical development over the course of the 20th century.