It was not until the monsoon ended in October that activity heated up again. Giap sent the 308, 312 and 316 Divisions south-west into the Thai Highlands, towards Laos. Their first target was the French position at Nghia Lo, a ridge between the Black and Red Rivers, together with attacks on Gia Hoi and Van Yen. Despite initial fierce resistance by the Vietnamese garrison, Nghia Lo fell to "human wave" assault by the 308 Div on 17th October, and the other garrisons in the area fell back on the Black River - they were saved from destruction by the sacrifice of 6e BPC, who were dropped at Tu Le as a blocking force, suffering great losses. (Though Gia Hoi, which had been surrounded by the 312 Division since 15th October, was successfully relieved and evacuated by the paras). Many of the CFEO troops reached Na San, where a fortified base (supplied by airlift) was quickly established as the only viable position in the area. But, suddenly, all of north-west Tonkin and the Laos border area was open to the VM.

Salan had regarded the Nghia Lo attacks as a diversion (expecting a VM attack on the Delta once he had committed reserves). When this did not occur, he decided to launch an offensive into the Viet Bac north of the Delta. He expected Giap to react by withdrawing from the Black River, at which point a set-piece battle in the VM heartland would not only weaken Giap militarily, but also would reduce their credibility with the local populace. The Nghia Lo position could then be regained, and the VM kept out of Laos.

To carry out this audacious plan (which was, after all, a serious gamble), Salan decided to strike along the line of the Clear River and RC2, and assembled a force of 30,000 troops (the largest French concentration yet seen in Indochina) to do so. These included four Groupes Mobiles, two Sous-Groupments Blindés (1er Chasseurs and 8e RSA) and a Dinassaut (DNA 12) on the Clear River. The operation was given the codename "Lorraine".

The land forces assembled at two jumping-off points: Trung Ha on the Red River, north-west of Son Tay, and Viet Tri on the Clear River to the north-east, and advanced on the 29th October, aiming to link up at Phu Tho (some 32km/20 miles to the north). However, VM regional troops fought strong delaying actions and the link-up did not occur until 5th November. The lack of "mainforce" opposition did raise CFEO confidence, and they set off deeper into the jungle highlands.

On 9th November, 2,350 paratroopers of 3e BPC, 1er BEP and 2e BEP dropped on a rough DZ near the VM supply-base at Phu Doan (Operation Marion), and armoured units of GM 1 and 4 moved up RC2 to relieve them, with support from the marines of the Dinassaut. In this phase of the operation, the French captured a haul of VM supplies (precise details vary - see below) including 4 Soviet-made Molotava trucks (which surprised their intelligence service!). From Phu Doan, the main CFEO force advanced to Phu Yen, while strong patrols were sent out along the roads north (to Tuyen Quang) and west (to Yen Bay), setting up blocking positions against the expected VM counter-attack.

But where was Giap during this French assault? That wily general had, in fact, decided to bluff it out and hold his positions on the Black River. Fully expecting the CFEO to outrun its supply lines, he sent only two regular VM regiments (one each from the 308 and 316 Divisions) towards Yen Bay from the Black River, and simultaneously ordered the two Divisions surrounding the Red River Delta (304 Division to the north, 320 Division to the south) to increase their guerrilla activity and thus encourage Salan to withdraw the "Lorraine" forces.

By mid-November, Salan realised that Operation Lorraine had failed in its objectives. Giap's mainfoce had not been brought to battle, and the CFEO was now garrisoning a useless finger of land pointing into VM territory. The air supply system was already overstretched, and convoys by road or river were proving costly in the face of ambushes by VM regional forces. Therefore, on 14th November Salan gave the order to withdraw behind the De Lattre Line.

This initially went smoothly, but on the 17th November, the two VM regular regiments that Giap had sent back were in the Phu Doan - Phu To area, and 36th VM Regiment (from the 308 Division) set up a large-scale ambush at the Chan Muong gorge, where RC2 wound through a steep-sided, jungle defile - only 150m wide at best. When a French convoy consisting of units from GMs 1 and 4 (BMI, II/2e REI, 4e BM/7e RTA, RICM tanks) entered, heavy mortar fire stopped them, and infantry assault caused serious losses in two heavy ambushes. Only furious action by the tanks of the van and rear-guard prevented total anihilation. The paras had, fortuitously, withdrawn down RC2 on the 16th November. Further such ambushes were sprung on the retreating CFEO during the next week, inflicting a total of around 1,200 casualties. French air-cover prevented even heavier losses.

While the CFEO had seized supplies, Giap quickly made up for these from his Chinese suppliers, and he was still in position to threaten Laos. While "Lorraine" was a well-conceived conventional operation, Giap had shown once more that he was far from being a conventional opponent! Salan had received a bloody nose, and Giap had lost virtually nothing.

Taking advantage of the situation, Giap counter-attacked and took two outposts (Ba Lay and Moc Chan). Then, in a misjudged movement, he ordered 308 Division to assault the position at Na San - where the remnants and isolated garrisons had retreated to a scratch-defensive position after the Nghia Lo debacle. However, the garrison had been reinforced and had fortified the camp with 3,500 mines and belts of wire. The garrison consisted of 3e BPC, 1er BEP, 2e BEP, III/3e REI, III/5e REI, two Tirailleur and two Vietnamese battalions, supported by artillery. The VM assault was launched on 23rd November. Fighting was heavy, but the VM had (for once) been mistaken about both the size and determination of the garrison. Despite strongpoints changing hands, the VM realised that the assault was futile and withdrew on the 3rd December. This was a morale-boosting success for the CFEO, but gave a false view that such air-supplied bases could be held against all-comers, even in the middle of enemy territory. (As this piece concerns "Lorraine", I have given only a brief account of Na San - I hope that we can write up a fuller description at some point).

Despite Na San, the autumn of 1952 was a great success for the VM, and acted as a springboard for the advance into Laos during 1953.

Captured Material from Phu Doan

There are two lists of the captured material from this base (seized by the paras in Operation Marion). One is from Bernard Fall, the other from General Yves Gras (both cited in Pierre Labrousse; "La Méthode Vietminh"):
 

While I have used the abbreviation "VM" above for "Viet Minh", in fact by this time the Viet Minh had been renamed "Lien Viet". However, it is standard in Western accounts at least to keep the term "Viet Minh" for all Vietnamese communist guerrilla movements during the period 1945-54 at least.

Supplies were beginning to become more standardised at this time, and photos of 1er BEP troops in Operation Marion show most dressed in the French 1947 fatigues (camouflaged or not), with bush hat, US webbing, and armed with the US M1A1 carbine.

• LABROUSSE (Pierre), La méthode Vietminh : Indochine, 1945-1954, Paris : Charles Lavauzelle, 1996. ISBN 0-7025-0387-X