Social revolutions have been rare but momentous occurrences In modern world history. From France in the 1790s to Vietnam in the mid-twentieth Century, these revolutions have transformed State organizations, class structures, and dominant ideologies. They have given birth to nations whose power and autonomy markedly surpassed their own prerevolutionary pasts and outstripped other countries in similar circumstances. Revolutionary France became suddenly a conquering power in Continental Europe, and the Russian Revolution generated an industrial and military superpower. The Mexican Revolution gave its homeland the political strength to become one of the most industrialized of postcolonial nations and the country in Latin America least prone to military coups. Since World War II, the culmination of a revolutionary process long underway has reunited and transformed a shattered China And new social evolutions have enabled decolonizing and neocolonial countries such as Vietnam and Cuba to break the chains of extreme dependency.

Nor have social revolutions had only national significance. In some cases social revolutions have given rise to models and ideals of enormous international impact and appeal–especially where the transformed societies have been large and geopolitically important, actual or potential Great Powers.