INTELLIGENCE REPORTS AND ANALYSIS
While MAGIC messages provided a windfall of information regarding Japanese intelligence operations, other more conventional methods were used by counter- intelligence organizations to provide an analysis of the subversive operations. For years prior to the Pearl Harbor attack, surveillance, informants, wire taps and infiltration, among other means, were used to evaluate the potential enemy's efforts.
As MAGIC intelligence became available it was "sanitized" to conceal its source. It was then incorporated into the framework of conventional counter-intelligence analyses. Many of the contemporary reports reproduced in this book were written by individuals and organizations without direct access to MAGIC. Others include "sanitized" MAGIC information.
Excerpts from two of the many reports which are reproduced in their original form in this book are provided.