From the back cover:

From the earliest planning stages of the German counter-offensive in the Ardennes, Hitler was convinced of the importance of taking the Meuse bridges. He resolved that, when his forces broke through the US lines, one special unit should be dressed in American uniforms and issued with American weapons and vehicles. In this guise they could take advantage of the surprise and shock of the breakthrough, and move forward to the Meuse bridges as if they were retreating Americans. Jean-Paul Pallud details their organisation and the fateful sequence of events that followed.