ABSTRACT
This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book focuses on the relationship between unilateral acts and estoppels. It discusses that recognition was then further delayed by negotiations between Spain and the United States over Florida, and occurred only in 1822 once those were completed as part of the famous "Monroe Doctrine". The book outlines the doctrine of unilateral acts from their nineteenth-century origins up to the twenty-first century. It examines how, over the course of the nineteenth century, international law began to grapple with these acts in a meaningful way; by the end of the century these acts were, at times, considered to be binding through a state's tacit or actual consent. The book explores the doctrine of unilateral acts in "modern" international law, a process that, as noted earlier, has its roots in the nineteenth century.
