This book will become mandatory reading for future diplomats and especially for those stationed in Washington. The historical background will show the usefulness of mature and persistent policies, a starting point for any negotiation. And they will add the care that must be taken, not only in the preservation of archives, but also in the warnings that must complete any information that a diplomat transmits, even if it seems truthful at first sight, because you will be charged if it turns out to be false or ridiculous, as shown by the examples in this book.Constructing history is a work, a method by which Dr. Marcano also demonstrated the raison d'être of his research: to discover, to sustain successfully a contribution to scientific progress. His previous book "Methodology of Legal Research," plus the success of his research, and his dedication to diplomacy, truly encourage us to recommend the reading of this work and allow us, with gratitude, to undertake this prologue.