Beginning 11 December, "CT" commanders began reconnaissance of forward areas as if in preparation for an attack. Beginning 12 December, some real tanks were moved up to Osweiler and at night were tripled by sonic means. On that day, too, the 75th began "fading" from the area and fictional columns were reported by spook radio to be moving north. The ruse was complete about a fortnight later when the real 75th came in on the northwest slops of the "bulge" near Marche, Belgium.

Again there is no complete confirmation as to the success of Operation KOBLENZ. In an evacuation hospital a few days after the German counteroffensive began, a soldier from the 4th Infantry was heard to remark: "I’d like to get my hands on those elusive bastards of the 75th." Also reported was a PW statement from the 4th Infantry 12th Regiment (which held Echternacht) to the effect that the German thought he had been captured by the 75th Infantry Division.

Operation KOBLENZ (Phase II) was scheduled to begin 21 December using practically the same scenario as Phase I but playing slightly to the north. The 23rd was destined to act in its advisory role and also to impersonate the 76th Infantry Division – which, incidentally, reported into this exact location five weeks later. Although no formal cancellation of Phase II was ever made, it soon became obvious that it would never be attempted – especially after the 23rd Liaison Officer with VIII Corps lost his trailer in Bastogne.

On December 16th, the German counterattack was launched after the 23rd had returned to its base in Luxembourg. Then, as the official chronology states in terse, unexcited prose: "Organization alerted, documents and records placed in vehicles under guard for immediate departure. Rubber items and special equipment prepared for fire. Guard doubled. Machine gun nests set up for defense of sector surrounding billets. Attacked by air; 23rd gunners posted on roofs fired at enemy planes during entire night." What the official report leaves out is the enthusiasm with which those guns were fired. It was the first and last time they were to have been shot at the enemy.

The danger to Luxembourg City was not great enough to force the retreat of the 23rd but the arrival of thousands of fighting reinforcements necessitated the evacuation of all 23rd units. By 21 December, the city housed four major headquarters: 12th Army Group PAC; General Patton’s Third Army, XII Corps and the 80th Infantry Division. The 4th Infantry was less than a mile outside of town. On this date the 23rd columns were streaming ignominiously westward to some cold, dirty flophouse barracks in Doncourt near Longuyon, France. Only 23rd headquarters remained behind and they decided to stick it out in the Italian Legation with Mme Nestgen.