concentrate about Lublin and Chelm respectively; otherwise they were to divide, one going to the right of the defensive wing about Shavli, the other continuing S. to Brest and Kobryn. Supposing that this proved unnecessary, the two armies, from Lublin and Chelm respectively, were to take the offensive against the left of the Austrian armies in Galicia. The right of these meantime would be attacked by two other armies, advanc- ing from Dubno and from Proskurov. These armies were given special precedence in their equipment, so as to be ready to act early. At Odessa, a minor army of reserve divisions was to be assembled to watch Rumania.
Defensive or offensive as the case might be, these preparatory engagements were all assumed to be in progress before the full concentration had been effected. Including the Petrograd army, only 28 out of a total of 37 active corps were comprised in the dispositions, and the reserve divisions formed on mobili- zation were not counted upon for immediate service. The remainder, in so far as no new complications occurred to tie them to their peace regions (e.g. Caucasus), would become suc- cessively available and constitute a mass of manceuvre or a pool of reinforcements, according to the course of events.
On mobilization, accordingly, the allocation of troops was as follows:
I. Army (Rennenkampf). Niemen, including Shavli. II., III., IV., XX. Gd., I. Corps. (As soon as relieved by reserve divisions [XXVI. Corps] at Shavli, XX. Gd. was to proceed to IV. Army.)
First task: protection in front of Niemen line, on that line, or if necessary further back towards Vilna. Second task: advance to bind the German forces on the lakes and Angerapp.
II. Army (Samsonov). Narew. VI., XV., XXIII., XIII. Corps. First task: protection of Bpbr-Narew-Bug line and reconnaissance into Mlava-Neidenburg region. In case of heavy German offensive, the region of Bialystok to be protected at all costs. Second task : invasion and conquest of E. Prussia via Mlava, turning the lakes. (These two armies had each several reserve divisions allotted.)
IV. Army (Evert). Concentration area Lublin. - Grenadier, XIV., XVI.. XVIII. Corps.
V. Army (Plefoe). Concentration area Chelm.: V., XVII., XIX., and XXV. Corps.
Both for attack of N. front of Austrian armies in Galicia.
III. Army (Rttzsky). Concentration Rovno-Dubno. IX., X., XL, XXI. Corps.
VIII. Army (Brussilov). Concentration S. and W. of Proskurov. VII., VIII., XII., XXIV., III. Caucasian Corps.
Both for attack of N.E. and E. front of Austrians in Galicia.
The I. and II. Armies formed the north-western front under Gen. Zhilinsky (succeeded after the first operations by Ruzsky), the IV., V., III., VIII. the south-western front under Gen. Ivanov, whose Chief of Staff was Alexeyev.
The VI. Army (Grand Duke Nicholas) was the title of the Petro- grad force, the VII. (Nikitin) that of the Odessa troops.
(In the event of German offensives developing on a large scale, requiring the adoption of the rear line of rail-heads, the IV. Army was to be switched en route to the right of the I., and to it instead of to the VIII., the XXIV. Corps was to go. It would also become part of the north-western front.)
The peace-time scheme, as thus outlined, was at once modified in the early days of mobilization, not so much in intentions as in allocations of force. No commander-in-chief of the whole was appointed before the war, as the Tsar was undecided as to whether to take command himself. At the outbreak of war the Grand Duke Nicholas, Commander of the VI. Army, was appointed. He had taken no part in drawing up the scheme, and his own ideas differed somewhat from it. He therefore formed a new scheme, or rather a modification of the basic scheme, whereby the Guard and I. Corps were dispatched to Warsaw (instead of to the I. Armyf to form the nucleus of a IX. Army, and the VI. or Petrograd Army was reduced first to one corps, and then to reserve divisions only. The first corps to leave was the XVIII., originally intended for the IV. Army but now assigned to the IX. (replaced in the IV. by the III. Caucasian Corps taken from the VIII. Army). The XXII. followed towards the end of August, joining the I. Army in lieu of the Guard and I. Corps. Further, a number of the reserve divisions accumulating behind the I. and II. Armies were con- stituted a little later as a X. Army with the mission of connect- ing the I. and II. Armies but too late to avoid the catastrophe of Tannenberg.
Mobilization and concentration proceeded rapidly. The cav- alry divisions allotted to the Prussian front were detrained complete by the yth day of mobilization, the infantry corps by the i^th day. On Aug. 14 the Grand Duke informed the French ambassador that the I. and II. Armies would open their offensive on the morrow, considerably sooner than was expected by the French, who only began their advance on that day.
The " preventive " offensive that was to lead to Tannenberg was thus launched on Aug. 14. Its objects were, partly, the accelerated fulfilment of the original plan of campaign (at the lowest, the active flank defence of the northern corridor, now being traversed by a IX. Army as well as the IV.); and partly, the desire to aid France by startling the German command into making detachments to the E.
Plans of Campaign Central Powers. The problem of war on two fronts had for many years been anxiously studied in Germany and it had been generally accepted in principle that a simul- taneous offensive E. and W. was impossible. In the time of the elder Moltke, the difficulty of defending the long, open eastern frontier, as compared with the relative ease with which the short, strong line Thionville-Strassburg could be held, had decided the great general staff in favour of choosing the east as the offensive theatre; and this plan held the field, with few modi- fications, until Schlieffen came into office as Chief of the General Staff and reconsidered the military position. He decided that the first offensive must be directed against France, but in such a way as to insure the quick and complete destruction of the French army, i.e. by using Belgian avenues for the envelop- ment of its left. His solution of the two-front war problem, therefore, was to prevent its happening: neither he nor his successor, the younger Moltke, seems to have dealt exhaustively with the case that actually arose, i.e. that of a prolonged contest in whu:h the centre of gravity constantly required to be shifted from E. to W. and vice versa. An important factor, perhaps the ruling factor, in the decision was the assumption that it would be impossible to bring the Russian army to decisive battle; owing to its slow assembly, the distances to be traversed in order to reach it required a time allowance which the western defensive, at grips with the highly trained and efficient French army, could not insure for it. Moreover, with unlimited space behind them the Russians were regarded as having every chance of avoiding a decision for as long as they wished to do so, and the re-distribution of the Russian peace garrisons after 1910 (which pointed to the choice of the rear line Kovno-Bialystok-Brcst as the probable line of entrainment) confirmed the conclusion. Two possible offensive directions were considered, that from the Mlava region against the Narew line, and that from the lake front by Wirballen and by Augustowo and Suwalki against Kovno and Vilna. These alternatives and their meaning have been alluded to already. The choice was a difficult one, hardly to be settled except ad hoc; it was to be the chief bone of contention between Falkenhayn and Hindenburg in the 1915 campaign. But even the second, and more promising, line of operations would not lead to the enemy's rear if he abandoned all Poland at the outset, and concentrated between Kovno and Brest.
In fact such a course of action was provided for in the Russian concentration scheme. But the alternative preferred by the Russians was an offensive, or two offensives, carried out by the readiest portion of their forces, and their alternative naturally engaged the attention of the Central Powers in the years after 1910, when the war-readiness of the Russian army was evidently being improved with menacing rapidity. The defence against such an attack could not readily be combined by the two Central Powers because of the salient W. of the Vistula ; on the defensive, therefore, Germany and Austria-Hungary formed two theatres, either or both of which might be the target of enemy offensives of uncertain power. Further, the entire peace forces of the Central Powers, taken together, were not equal numerically to the peace forces of Russia, and the adhesion of Turkey, and still more that of Rumania, to their side was problematical. If the bulk of the Russian forces concentrated on the forward line, then there were only two practical alternatives for the Central
