A buffer state is a smaller country located between two or more powerful nations, acting as a neutral zone to prevent direct conflict between them. Historically, buffer states have served as geographical buffers, reducing the likelihood of war spilling into the powerful neighboring states.

Examples include Afghanistan during the 19th century, acting as a buffer between British India and the Russian Empire. These states are often geopolitically vulnerable, as their strategic position can make them targets for influence or control by larger powers.