A formal agreement between two or more mostly sovereign states to cooperate in specific areas. International alliances often have military aspects but can also include cooperation on a broad range of issues, such as security and development. International alliances have been a part of world politics for centuries. One of the first theories of why countries form alliances was presented in a 7th century Indian text, the Artha-shastra. That theory argues that alliances allow smaller states to gain resources, prestige, and power from larger ones without jeopardizing their own independence. More recently, scholars have embraced neorealist and neoliberal explanations of why countries pursue international alliances.
Modern alliances are more complex than those of the past. They usually involve a diverse coalition of old and new partners, and they typically have to deal with shifting political conditions.
The formation of international alliances in the wake of decolonization was an important step for many newly independent states in securing their sovereignty and addressing the challenges of economic development and security. These alliances provided members with military support against external threats and promoted shared interests like regional stability. Some alliances even included economic cooperation initiatives to promote trade and development among member states.
As the global political environment has changed since the Cold War, NATO has continued to adapt its mission. Its members have expanded from the former Soviet and Eastern European states to include allies in the Mediterranean region. They have launched faraway missions to prevent human suffering in places such as the Middle East, demonstrating that NATO has a future beyond the North Atlantic.