Prussian Strategic Concepts in the Years 1815–1819

Chapter 7 Prussian Strategic Concepts in the Years 1815–1819

During a Generalstabsreise between Königsberg and Insterburg (Wystruć, now Chernyakhovsk), one of the adjutants accompanying Alfred von Schlieffen exclaimed loudly his awe at the view of the Pregel (Pregoła, now Pregolya) val- ley in the light of the rising sun. Schlieffen’s response was brief and to the point: ‘An unimportant obstacle’.1 This story, usually used to illustrate Schlief- fen’s narrow range of interests, also shows the main problem with Prussian war planning throughout the whole 19th century, the appropriate appreciation of geographic conditions in potential areas of operation. The geostrategic position of the Kingdom of Prussia after the Congress of Vienna was considered unfavourable.2 In his momorandum of 1817, Boyen in- dicated that the country’s position was determined by two main factors. The situation had worsened since Frederickian times when Prussia had one powerful neighbour, whereas now there were three. This forced Prussia to consider the possibility of fighting a war on two fronts (doppelte Krieg).3 This appraisal was shared by other officers, including Clausewitz4 who considered Prussia, as a result of the Congress of Vienna, to be compressed between two ‘colossuses’, France and Russia.5 Both were to be considered members of an anti-Prussian coalition, especially in the equivocal policies of Tsar Alexander. In consider- ation of the detachment of Prussian territories, Boyen felt that the political and financial significance of its eastern and western provinces meant that it was unthinkable to place the main line of defence on the Saale, as had been the case in 1806. It was difficult to depend on the political constellations in 1815 when Prussia was allied with the whole of Europe. In the event of war on two fronts, Prussia’s strategic triangle was Trier, Cosel, and Memel (Klaipėda). This triangle, on either side of the Elbe, whould constitute almost a hundred miles. Support would be provided by a strong reserve corps.6 In a memorandum of the same year, Boyen stated that Prussia’s situation should be considered in the context of each province’s relation to its neighbours. The aim was to hinder

1 J. Snyder, The Ideology of the Offensive. Military decision making the disasters of 1914 (Ithaca– London, 1984), 133–134. 2 Cf. Chapter 1. 3 ‘Boyens Darstellung’, 61, 68–69. 4 ‘Unsere Kriegsverfassung’, Clausewitz, Verstreute, 277–299. 5 Ibid., 299. 6 ‘Boyens Darstellung’, 69.

Prussian Strategic Concepts in the Years 1815–1819 199 enemy movements, making full use of natural obstacles in the terrain, especially rivers, as well as the engagement of inhabitants.7 He considered France as the most dangerous neighbour, with its ability to mobilise 29 million citizens, and Russia, the border with whom needed to be defended.8 Taking stock of the situation, Boyen saw four main problems with the Prussian war system. First, territories on the left bank of the Weser and east of the Thuringian Forest did not constitute a cohesive defence system and were only partially protected territories of smaller states. This meant that an attack on them would have to come from German Confederation territory or be directed against a larger number of states belonging to the Confederation. This situation was unfavourable, for instead of a group of smaller states, Prussian territories on the Rhine bordered the powerful states of France9 and the Netherlands. To hold these territories required an independent army, which would have to operate in isolation for a long period of time. The situation required allies to increase security in the western provinces. Boyen believed Prussia’s military position with regard to Austria had not changed significantly. The only modification was that Austria had lost its possessions in the Netherlands and Breisgau, which meant that Britain no longer showed interest in its territories or detach- ments that were stationed there. The greatest changes were in the military situation on the eastern border, where significant territorial alterations had oc- curred. The previous border along the Bug and Narew made a Russian attack from the south difficult, as its army would expose its back to an attack from Galicia. Moreover, a Russian offensive would need to cross the Vistula, Bzura, and Warthe. In the new circumstances, Galicia ceased to fulfil its role and the rivers no longer provided effective protection. The Prussian border had be- come open, and Berlin was only protected by the Oder line with fortresses in Küstrin and Glogau, and a resistance point in Wrocław provided that its defensive properties were restored. Boyen believed the situation necessitated the division of Prussian forces into two parts, supported by trained reserve units and fortresses.10 Prussian war preparations in the 1815–1819 period were per- ceived in parts concerning eastern and western provinces. In both instances, the issues concerned terrain and appropriate fortifications.

7 GStA pk, vi. ha, Boyen, No. 309, Nach welchen Grundsätzen, 3–4. 8 Ibid., 8. 9 Significantly, in the same period, the French also considered their borders to be unfavourable. Particularly worrying for them was the loss of control of Luxembourg and fortresses on the Saar line, hindering defensive actions to the east of the Vosges mountains; Cox, The Halt in the Mud, 30–33. 10 Ibid., 9–13.