Main idea of the book or theme

The main idea of the book is to inform the reader, in what truly happened on D-Day. An what led up to it and what actions had to be taken and as well what men stepped up and led his men to victory. Even, with the great losses that day brought. But, also what secret missions were taken to get as much information as possible before going in and getting the job done. To minimize the death toll and over all the main idea of this book was inform people of a day that changed our history for ever.