In his March 1810 memorandum Barclay had stated that Russia’s western borderlands were very weakly defended by man or nature. Many other officers expanded on this theme in reports written between then and June 1812. Russian military engineers were badly overstretched in these years. In 1807–11 the small corps of engineers was deployed in the Baltic seaport fortresses against possible British attack, in the Caucasus and in attempts to refortify strong-points taken from the Ottomans in the Balkans. From March 1810 it was also lumbered with the immense task of fortifying the western borderlands at breakneck speed. As was pointed out in a number of memorandums, fortresses bypassed by Napoleon would be a big threat to his fragile communications. This would slow down his advance. More importantly, a retreating army with no fortresses in its rear had nowhere secure for its supplies and baggage, and was therefore always obsessed with the need to protect them. In this situation an army tended to retreat quickly since only distance provided security.50
But fortresses, however necessary, could not easily be built from scratch in two years. On their southern flank, the Russians succeeded in preparing Kiev’s defences for a siege and constructed a strong fortress at Bobruisk. On their northern flank, Riga was strengthened though the commander of the corps of engineers, General Oppermann, doubted whether it could hold out for long against a serious siege unless its garrison was very large. Once the new fortress of Dünaburg on the Dvina was completed, Oppermann wanted to move all supplies and stores there from Riga, since he feared that the latter’s fall to the French would otherwise threaten the logistics of the main Russian armies.
Unfortunately, however, Dünaburg could not be completed by the summer of 1812. This meant that the entire central sector of the Russian defence line was open. As Bennigsen pointed out, this central sector gave access to the core territories of the Russian Empire, including the army’s likely supply bases in Moscow and Smolensk. To make matters worse, this huge central sector had no natural defences of real value. Wolzogen had obeyed his orders to choose a defensive position on the river Dvina and had selected the spot for a fortified camp at Drissa. Nevertheless he warned that the upper two-thirds of the Dvina was shallow and easily forded in summer. Moreover at most points the west bank was higher than the east, which put defenders at a serious disadvantage. Barclay received the same advice from an even more authoritative voice, namely General Oppermann, who told him in August 1811 that the river Dvina could not be defended against a serious enemy advance, ‘however good any specific position may be’. The reason for this was that ‘in summer the river is easily crossed, the areas close to its banks are almost everywhere open and easily traversed, and any position on or near the river’s banks can be outflanked’.51
Between Riga on the Baltic coastline and Bobruisk far to the south the only significant defence-works in June 1812 were the fortified camp at Drissa, way upriver on the Dvina towards Vitebsk, whose construction began in the spring of 1812. Alexander’s unofficial adviser, General Pfühl, made the camp at Drissa the key to his plan for the defence of the empire’s heartland. By the time Napoleon’s forces approached Drissa, Pfühl expected them to be exhausted and reduced in number after crossing a devastated Belorussia and Lithuania. If they attempted to storm the fortified camp in which the bulk of First Army had taken refuge they would be at a great tactical disadvantage. If they tried to move beyond Drissa then First Army could attack their flank. Meanwhile Bagration and Platov’s forces would be striking deep into Napoleon’s rear.
In principle Pfühl’s plan had much in common with Barclay’s proposals in March 1810. There was the same reliance on strategic retreat and devastating the abandoned territory; on fortified camps as a means to strengthen the defending army when it finally turned at bay; on the role of other Russian forces in striking into Napoleon’s flanks and rear. Pfühl had merely transported Barclay’s concept from the two flanks, where Barclay had seen the greatest threat, to the centre of the Russian line, which now seemed the likeliest target for Napoleon’s main blow. But Barclay’s fortified camps were to rely on the support of fortresses, Riga in the north and Bobruisk in the south. With Dünaburg gone, Drissa must stand alone. In addition, in 1810 Barclay had not anticipated that Russia would be invaded by an army of anything like half a million men.
Even in 1812 Pfühl was probably not fully aware of the size of Napoleon’s invasion force. Access to Russian intelligence material was confined to a very tight circle. By March 1812 Alexander, Barclay and their de facto chief intelligence officer, Petr Chuikevich, knew that even the first wave of Napoleon’s army would be 450,000 strong. A force of this size could both mask and outflank Drissa without danger. It could also block any attack by Bagration and Matvei Platov without difficulty. If First Army took refuge in Drissa, it might be surrounded and captured as easily as Mack’s troops in Ulm had been at the beginning of the 1805 campaign.
Nevertheless Alexander’s plan of campaign in 1812 at least on the surface revolved around the fortified camp at Drissa. The Russian army was to make a strategic withdrawal to Drissa at the war’s outbreak and would then attempt to hold the French on the line of the river Dvina. Perhaps Alexander genuinely believed in Pfühl’s plan. He always tended to value foreign soldiers’ opinions above those of his own generals, in whose abilities he usually had little confidence. In addition, Pfühl’s ‘scientific’ predictions as to the precise moment when Napoleon’s supplies would run out may have appealed to Alexander’s liking for tidy, abstract ideas. Undoubtedly the emperor believed that Pfühl’s plan was based on the same concept as Barclay’s earlier proposals. He will also have remembered that in 1806–7 Bennigsen had kept at bay for six months an enemy double his numbers. Nevertheless there is room for some cynicism. Alexander did not want Napoleon to penetrate into the Russian heartland, though he feared that he might do so. Any open admission that Napoleon might reach Great Russia in his initial campaign, let alone the circulation of plans based on such an idea, would have destroyed the emperor’s credit. If Napoleon was to be stopped short of the Great Russian border, Pfühl’s plan seemed the only one currently available. Should it fail, Alexander knew that Pfühl would be the perfect scapegoat. A foreigner without protection, he was also despised by the Russian generals as the epitome of a German pedantic staff officer who knew nothing about war.52
Though Alexander may have retained faith in Pfühl’s plan even in June 1812, it is very hard to believe that the experienced Barclay allowed it greatly to affect his thinking on how the war should be conducted, given the advice he had received from the army’s chief engineer. From Barclay’s perspective, however, the camp at Drissa did no harm. It absorbed almost none of his resources, since it was built with local labour. It was also a useful stopping point in the army’s retreat and almost unique as a place where stores could be established for the retreating army under some kind of protection. In any case, final decisions on Russian strategy rested with the emperor, not with Barclay. But the best guide to Barclay’s thinking immediately before the war is provided by a memorandum written by Chuikevich in April 1812. It says nothing about fortified camps in general or the camp at Drissa in particular.