'Nancy' was a US special forces operation to parachute an Office of Strategic Services operation group into the St Christol area of German-occupied France to strengthen the resistance movement and to operate against German communication systems on the Franco/Italian border in the region of Montgenèvre pass (12 August/16 September 1944).

The 'Nancy' operational group comprised 15 men including its commander, Captain A. Lorbeer, and most of the group’s men were of Italian extraction. The mission was organised in the algerian region of French North Africa, and was delivered to France in an adapted Short Stirling heavy bomber which took off from Blida at 20.45 on 12 August for the 'Armature' drop zone near St Christol, about 15.5 miles (25 km) to the north-east of the town of Apt in the Vaucluse region. The flight was straightforward, but the landing by parachute was more difficult as the terrain was uneven and frequently rocky. As a result most of the operational group’s men suffered cuts and bruises, though none of the injuries was completely incapacitating. The reception party comprised only a few resistance fighters, and these had no provision for the movement of equipment. Most of the operational group’s rations disappeared at this stage in the undertaking, but the team established itself in some woodland, where is was soon strengthened by the arrival of US airmen whose aircraft had been shot down but who had managed to evade capture by the Germans.

On 15 August, the Americans started a 250-mile (400-km) truck journey to the north-east into the mission’s designated operating area, and on the following day were supplemented by 30 gendarmes who had deserted from the German garrison at Briançon. A reconnaissance on 17/18 August located a pair of promising targets on the road linking Briançon and Montgenèvre. A wall 2 ft (0.6 m) thick and supporting a sharp curve was blown with 1,200 lb (545 kg) plastic explosive, the shattered wall tumbling down the side of the mountain and the curved road collapsing. The second target was below the first, and took the form of a reinforced concrete bridge some 30 ft (9.1 m) wide and 60 ft (18.3 m) long, and this was blown with 300 lb (136 kg) of plastic explosive.

On 21 August, the 80-man German garrison at Guillestre surrendered to the OSS group and some British officers on the assurance that the men would receive full prisoner of war status. The next day saw the destruction of two bridges near St Paul and Ste Marie. The larger of these was a double concrete span some 40 ft (12.2 m) wide and 120 ft (36.6 m) long, and 1,500 lb (680 kg) of plastic explosive were used in this pair of demolitions.

On 23 August, 1^st Lieutenant W. F. Viviani, the group’s second in command, contacted a US Army tank destroyer unit which had reached the outskirts of Guillestre, and provided the unit’s commanding officer with maps and local intelligence. On the following day, the group provided maps and data to 180^th Infantry, which was shielding the the right flank of Lieutenant General Alexander McC. Patch’s US 7^th Army advancing from the 'Dragoon' landing on the south coast of France toward Grenoble. While undertaking a reconnaissance of the Guillestre area in the Larche pass near the Franco-Italian frontier with British and US officers, the group came under fire near Meyronnes, and on leaving the valley blew a small bridge.

Between 26 and 29 August the group moved to Col de la Mayt near the border and located some old Italian barracks in good defensive position but a very poor sanitary condition. This had been occupied by 150 poorly clad and badly equipped Italian partisans. A three-man team was detached from the group to link with a well-organised resistance group, and in the several days it spent with this French party the team established the location of a large and highly productive ball bearing factory, which it reported for subsequent bombing by British warplanes.

On 3 September, in a break in traffic on a much used road at Fenestrelle, a team led by Lorbeer prepared a bridge for demolition and booby-trapped the surrounding area. Reconnaissance on the following day revealed that the bridge had been completely destroyed and the crews sent to repair it had been stopped at a distance from it by fragmentation grenades and time pencils used as fuses.

Five days later, on 8 September, the Germans took Col de la Mayt, but two days earlier the OSS Group had departed to gather at Abries. On 10 September all three of the teams which had been operating semi-independently of each other joined forces once more and some of the members of all three teams entered north-western Italy across Col St Veran. Between 12 and 16 September the other members of the OSS group moved into Italy and began to consider ways for possible joint operations with Italian partisans, but contact near Col St Veran with a party of some 30 Germans resulted in a firefight which led to the disintegration of the partisan force. Further plans for collaborative ventures were interrupted by orders for the OSS group to return to Grenoble.