ABSTRACT
The Introduction presents the reasons behind this book, as well as lays out some preliminary questions, including the state of the art and research aims. It also introduces the thesis advanced in the book, that is, that the prohibition of threats of force is a separate legal norm from the prohibition of the use of force; at the same time, the former reaches neither peremptory nor customary status. Next, the methodology developed in the book is discussed. Finally, the Introduction presents briefly the content of respective chapters.
