https://pjmedia.com/victordavishanson/recalling-the-battle-of-the-bulge/
Seventy-five years ago, at the Battle of the Bulge (fought from Dec. 16, 1944, to Jan. 25, 1945), the United States suffered more casualties than in any other battle in its history. Some 19,000 Americans were killed, 47,500 wounded and 23,000 reported missing.
The American and British armies were completely surprised by a last-gasp German offensive, given that Allied forces were near the Rhine River and ready to cross into Germany to finish off a crippled Third Reich.
The Americans had been exhausted by a rapid 300-mile summer advance to free much of France and Belgium. In their complacence, they oddly did not worry much about their thinning lines, often green replacement troops or the still-formidable Germany army. After all, Nazi Germany was being battered on all sides by Americans, British, Canadians and Russians. Its cities were in ruins from heavy bombers.
Yet the losing side is often the most dangerous just before its collapse.
In retreat, the Germans were shortening their interior lines. They had the element of surprise, given confident allies who assumed the war would soon be over.
The cold December weather would ground the overwhelming number of Allied fighters and bombers. The Germans aimed their assault through the snowy roads of the Ardennes Mountains to bowl over inexperienced or exhausted U.S. divisions.