last part (Part IV: "Conclusions").
1. General Observations
In estimating the military results of the campaign, it is generally stressed that the Polish army carried out an important task by engaging the major part of the German forces and thus allowing the Western Allies of Poland ample time for a leisurely mobilisation and preparations.
Apart from that somewhat passive task and the inflicting of heavy losses on the enemy, the resistance of Poland achieved another important object by revealing the operational methods of the German High Command and the fighting value of the different branches of the German forces.
Most of the views which have been so far expressed on the subject of the Polish defence plan and general development of forces contain a criticism of the weakness of flanks, of the insufficiency of reserves, and of the choice of a defence line (it is stated that it should have been placed behind the Narew, the Bug, the Vistula, and the San).
The consideration of the topography of the country, of the military possibilities, and of the plans and preparations of the Polish High Command throws some light on the subject and permits a sound estimate of the facts.
The German plan provided for three simultaneous blows, aimed at the centre and the two flanks. The first stage of the campaign was to consist in the cutting off of Pomorze and the preparation for the surrounding of the Polish western armies within the loop of the Vistula. In the second stage it was planned to carry out a wider encirclement beyond the Bug and the San.
Poland decided to resist and yield ground fighting; after taking up positions behind the defence line it was expected that the well-known and undisputable superiority of the enemy forces would be counteracted.
Such were the leading principles of the operations. Germany had a great ease of manoeuvre thanks to her mastery of the air. The original surprise attack gave her the initiative, which she could keep in her hands throughout the campaign owing to the superior speed of her armoured and motorised divisions, as well as to the mastery of the air possessed by the Luftwaffe.
Poland could not carry any planned manoeuvre to its conclusion, owing to the slow rate of movement due to the inferiority of her technical resources, which weighed heavily on every attempt at concentration or counter-action.
The sources which are accessible to-day provide a clear picture of the actual development of events, but they give little ground for a critical appreciation of the operations.
The first "Blitzkrieg" on a major scale provided, however, a great wealth of experience and data, permitting a valuation of the part played by new weapons and the method of their tactical use. The one-month campaign fought by the Polish army deserves to be studied especially from that point of view.
The ancient elements of warfare, such as leadership, morale, physical superiority, surprise, etc., have remained unchanged. In the sphere of manoeuvre, however, the present war brought about a complete revision of the relative importance of different means of transport. Motor transport leapt to the first place, together with the aeroplane, leaving the railways far behind.
Infantry marches can be used as a means of manoeuvre only within a limited tactical scope and on small distances.
The increased speed of action and speed of movement emphasises the element of foresight, planning, and efficient organisation of the disposable means on a certain territory. The calculation of time has to be set now to quite different limits than those of yesterday.
The principle of a most careful selection of the technical executors of the commanders' orders has been confirmed again by the Polish campaign. A still greater amount of experience and knowledge is to be expected of a staff officer.
2. New Weapons
The First World War brought new tactical methods, resulting from the use of fire concentrations both in defence and offence (the fire manoeuvre). The fire power, provided by guns, was limited in range and destructive effect, owing to technical reasons.
In the present war fire concentrations became more destructive and their range was increased to several hundred kilometres thanks to the use of waves of bombers following each other.
The last war gave only the first inkling of the power of the new weapons: the aeroplane and the tank. Their apptitude for mass grouping, their speed, and their range suggested new possibilities of breaking-through and of destruction.
The subsequent period of peace was used by engineers for improving the performance of both aeroplanes and tanks, while military experts worked out new methods for their use.
Thanks to careful observation, theoretical conceptions were confirmed and new practical data were collected in the course of various minor wars, especially during the last five years.
Germany, actively rebuilding her military power, was leading in all the fields, either openly or in secrecy. Examples are provided by the period of collaboration with Russia after Rapallo or the participation in the Spanish civil war. After 1933 no expense was spared on tests and experiments (some of them unsuccessful) carried out in the course of manoeuvres and training. Bloodless campaigns (the occupation of Austria, of the Sudeten, and of Czechoslovakia), although they were not free from failings, served to formulate definite principles, which were embodied in military publications and provisory regulations, known as "Merkblatter."
In Poland, as well as in some other countries, it was usual first to wait for the results of promising disarmament conversations and then to recoil from the spending of fantastic sums involved in the introduction of new weapons or defences against them.
But the price which we paid for the experience of 1939 was infinitely greater than any possible expense.
Although the Soviet intervention was directly responsible for the conclusion of the campaign, its issue was actually decided by air power and armoured divisions. This is a basic truth which should be ever present in the minds of those responsible for the security of any country.
Observations on the activity of those two fighting services form the centre of interest, as the others played only a subsidiary part; that is why I have dispensed in the present work with a study of the purely tactical aspect of the campaign and the conclusions to which it might lead. The available data and facts remain a subject for a separate study undertaken from a tactical point of view.
3. The Air Force and its Use
The air force acted as a separate arm, carrying out its own individual tasks, which included mastery of the air and the destruction of the whole country. Those two aims were achieved thanks to the inadequate strength of the Polish air force and anti-aircraft defences, as well as the small depth of the Polish territory. In view of the encirclement of Poland from the north and the south by territories under German control, no air operations had to be undertaken within a greater range than 400 kilometres.
The autonomous activity of the Luftwaffe suggests the following conclusions:
(1) The air attacks were carried out by surprise. In consequence everything that was not ready for action on the first day was immediately disorganised and thrown out of gear.
(2) The mass of bombers used by the enemy was so great as to cover the whole front and the whole country at the same time. The destruction was too widespread to make repairs possible and many services could not be restored.
(3) The continuity and the uninterrupted character of action caused the exhaustion of the resources of the defence and made even temporary reconstruction impossible.
(4) The long duration of certain actions, even if they were not particularly effective, tied up the defence and gave the impression that the attacking force was stronger than was actually the case.
(5) The mastery of the air was used for effecting landings, in order to promote sabotage and treachery behind the front lines, to spread panic or to carry out definite actions. In some cases larger detachments landed from the air attacked army headquarters or security units behind the front.
Every action was carried out by at least one squadron, generally flying at medium altitude. After 12th September there were also actions by smaller groups, probably designed to cover simultaneously the largest possible area. There is documentary evidence of over 420 group flights carried out by the enemy; 862 localities bombed, while Warsaw suffered 26 air attacks. These figures take no account of actions against troops, even when they involved the bombing of inhabited areas and towns. The number of air raids on non-military objectives gives the measure of the Luftwaffe in Poland.
As far as Poland was concerned, this action had the following results:
(1) It confused and postponed mobilisation, although it failed to prevent it completely.
(2) It paralysed the transports already on the third day, making it impossible to complete the concentration. It also rendered impossible any manoeuvre or re-grouping on a large operational scale.
(3) It threw out of gear the administrative machinery - as a consequence most orders either reached their destination too late or could not be carried out.
(4) It destroyed means of liaison and thus either diminished or supressed facilities for commanding.
(5) It made any movement of troops extremely difficult, reducing it to night alone.
The air force also collaborated with the army in respect of reconnaissance and directing of fire.
It was notable that the aerial reconnaissance was used almost exclusively in favour of armoured formations, or for the purpose of tracking the Polish air force.
Reconnaissance was generally carried out not as a separate task, but in the course of bombing or ground strafing flights. Advanced aircraft of a fighting formation sought out targets and informed about them their ground headquarters.
The collaboration with the army was aimed at superseding artillery, mainly heavy and long-range artillery. Such attacks were directed at first at the rear positions, gun positions and stores of the enemy, then turning towards the front line. Sometimes both the rear and the front were attacked simultaneously by two waves of bombers.
It is known, however, that the destruction of permanent buildings was thorough and effective. The losses suffered by trained, disciplined, and properly disposed troops on march were relatively slight. At any rate ground strafing caused more casualties than bombing.
The proportion of non-exploded bombs was fairly high - 30-50 per cent.
The moral effect and the confusion produced by the explosions of a large number of bombs were always so strong that some time was needed to restore the men to normal. The same moral effect was noted in the course of night fighting, when tracer, flare, and incendiary missiles were used. The sound effects used by the enemy (screaming bombs, powerful sirens with a high-pitched shriek, etc.) also required a certain nervous effort of self-control on the part of the soldiers.
The inadequate Polish anti-aircraft artillery helped to keep the enemy aircraft at a certain altitude, but it was not particularly effective when attacks on large targets were concerned.
The fighters proved to be a really effective and reliable means of defence, inflicting heavy losses on the enemy, dispersing the bomber formations, and sometimes even forcing them to abandon their mission. But the fighters could be effective only if they were available in large numbers and kept in constant technical and fighting readiness. In Poland, where neither of those conditions were realised, the German bombers and dive-bombers generally carried out their attacks without the protection of ther own fighters.
Generally speaking, the Luftwaffe, secure in its mastery of the air and impunity in view of the inadequate ground defence, carried out in its actions against the army and the whole country the task which is generally imposed on the air force by the modern theory of war. It paralysed the work of the country, immobilised or destroyed material, and foiled the efforts of the defence.
4. The Armoured-Motorised Formations as an Instrument of Lightning War
Armoured-motorised units were used on a big scale for the realisation of the operational plans of the High Command. They were its principle instrument of action, responsible for the execution of the whole plan.
Every armoured-motorised unit was composed of several elements charged with three tactical duties respectively: reconnaissance; the capture of certain objectives; and the preparation of advance by overtaking.
An analysis of the battles reveals that most of the mobile fighting was done with the fire of armoured machine-guns or artillery. Wherever there was some stabilisation of the front, or a technically prepared territory was encountered, the enemy reverted to the old tactical methods, consisting of reconnoitring a position, preparing an attack with fire and then attempting a break-through, eventually followed by a deeper consolidation of the advantage thus obtained.
The operational use of armoured forces was based on the typical features of that arm: the concentration action of armoured fire and the speed of the tanks.
A few general principles may be formulated:
(1) A division advanced some light elements in order to seek out the enemy front, establish contact, and form flanks. If there was no possibility of an encircling action through the point of least resistance, a frontal attack was carried out and then the speed of the armoured forces was used for penetrating as far as possible and thus preparing the way for the next wave.
(2) A complete armoured-motorised division was used in each of the proposed directions of attack. If the task in hand required it, they were coupled with other fast divisions, making use of the gaps which might be discovered, or of the breach made by the tanks.
(3) After a successful break-through the front line, the motorised divisions penetrated very deep behind the front, in order to escape the counter-action and prevent the re-organisation of defence on the same line. If they encountered serious resistance, reinforcements of light motorised forces, or infantry brought in lorries, were immediately sent up.
(4) In the main direction of action, in the group of General Reichenau (the 10th Army), a group of six armoured-motorised divisions was specially formed. Their action consisted of the following stages: first, the resistance of the front line positions was broken and a deep penetration into the defence system was effected, while the next wave of attack was endeavouring to engage the flanks of the breach. In the next stage, an attempt was made to roll up the wings of the defence by a vigorous action, while a further movement was effected at the maximum depth of penetration in the main direction of advance by means of reconnaissance and the capturing of certain points in the region concerned. In the third stage, light fast divisions were inserted into the breach and they spread fanwise into the country, while the continued pressure on the flanks of the original front on both sides of the breach caused a concentration of Polish forces at those points, where they were engaged by infantry.
Such was the general outline of the operation north of Czestochowa, designed for a break-through towards the Vistula, Warsaw and Sandomierz. At the same time the flanks of the Lodz Army were engaged, the resistance of the reserve army was broken down with a side movement, and the positions of the Kielce group were passed by after the destruction of the 7th infantry division. The same method was used by the action of the concentrated two armoured divisions south of the line Chojnice-Tuchola-Swiecie, with a by-passing of the defence at Czersk. A similar action was carried out from Jordanow towards Rzeszow-Lwow and from Krosno through Chyrow towards Lwow, and after the break-through at Wizna towards Brzesc and Kaluszyn. In the last two cases the development of the battle was somewhat different, as there was a counter-action of the Polish troops and they did carry out a centrifugal manoeuvre.
In the course of all those actions there was a close collaboration with bombers and attack squadrons of the Luftwaffe. They attacked the country far beyond the front line, destroying railway and road junctions, all means of transport and larger towns, and reporting at the same time the disposition of the defences, as well as carrying out the functions of long-range artillery.
The break-through battles were fought in strict accordance with the regulations and instructions. The armoured forces accompanying infantry established contact, and after making an attempt at breaking through with their sheer weight, which generally failed, they formed a curtain of fire in front of the Polish defence lines. Lighter elements moved in search of the flanks. The remaining forces of the column launched immediately a frontal attack, using all their available weapons, unless a flank or weak point was previously discovered by the light elements. Each of the successive stages of the battle followed by short intervals of about two or three hours, during which the tanks, the infantry, and the artillery carried on their concerted action. The attacking troops were often brought up to the line by motorised transport within sight of the defending forces.
It is to be observed that there was not a single action of advanced elements which was not supported by artillery fire. Combined groups were always used: motor-cycles with machine-guns, light tanks and motorised artillery on caterpillars.
Every attack was prepared by artillery fire concentrated on the point selected for a break-through and repeated after a few hours`interval in case of failure.
Such a method of action of armoured divisions completely changed the character of mobile fighting. It also changed the method of using the reserves at the disposal of the senior commander. In both cases it was a matter of first overtaking the speed of motorised weapons and then breaking the armour. The local defence had to anticipate the blow and the counter-attack. An excellent example is provided by the action of the 58th infantry regiment at Emiljanow, where a wave of tanks surprised the attack of the 14th infantry division in the course of its preparation and was arrested by the defence on the positions of the reserve regiment.
The Polish idea of organising motorised anti-armour units for every division was therefore correct. They consisted of a battery of anti-tank guns with machine-guns for their protection. They were organised in autonomous motorised brigades, known as O.M., designed to use their speed for forming a barrier behind the front of the army, or on its flank.
The use of divisional reserves, or reserve armies, for the purpose of protection by traditional counter-attack, proved entirely ineffective, for it is necessary to stop the wave of tanks before engaging in a battle in which their armour may be destroyed.
A decision of retreat at the moment of a break-through by armoured forces tended to favour the plans of the enemy. On the contrary, an army should stay on and endeavour to cut off the armoured divisions which penetrate behind its front, for the purpose of subsequently destroying them.
As the financial limitations imposed on the Polish army did not permit the establishment of sufficiently strong armoured forces, the cheaper solution was adopted in the form of providing the troops with effective anti-tank weapons. The gradation of the means of defence and their organisation depended on the tasks imposed on each type of command. The means used by a smaller unit are bound to be different from those reserved for an army. No unit, however, should be without anti-tank weapons.
The arrangement of reserves in depth was not sufficient if they were not provided with mobile anti-tank weapons. It was also not sufficient for an army front to have several successive lines of defence, with anti-tank obstacles and human reserves, if it had no means for overtaking the fast enemy units, piercing their armour, and cutting off their fuel supply. It is to be observed that the German regulations ordered every division to carry four days' supply and that it provided for ten hours of action per day. Those facts indicate the possible lines for counter-action.
The Polish army was equipped with anti-tank ammunition, grenades, and land mines, but their supply was small and calculated for short actions. There were special anti-tank rifles in every infantry platoon and anti-tank guns in battalions. They were very effective in action, but insufficient in numbers. Unfortunately the regiments and divisions were without special anti-tank units, while the 75 mm. field guns could be used for that purpose only to a limited extent, since they had to carry out other important duties. Besides, there were too few of them to go around. In consequence, every action was more or less confined to resistance on the line, as it was impossible to produce a barrage of anti-armour fire deeper than 800 metres, which could have dealt with mass and wave attacks. There were too few motorised brigades to be used operationally as movable barriers (the value of such units was well illustrated by the activity of the motorised brigade in the Cracow Army during its sixteen days of fighting).
The method of night attacks against the headquarters and parks of armoured divisions, used on several occasions by Polish infantry, gave excellent results. The enemy was compelled to provide his tanks and armoured cars with powerful searchlights, which blinded the attacking force and, when used in accordance with a definite plan, assisted defence fire at night. Finally the method of bombing motorised columns on march, and especially at their stopping-places, proved effective in delaying their progress. Several captured enemy reports confirm the fact that serious losses were inflicted by the Polish bombers. The method of cutting off motorised divisions from their fuel supply and thus paralysing their movements was not tried out. It could have become a practical plan only after 10th September as a consequence of the depth of the enemy penetration up to that date, and of the fact that the enemy was operating on territory previously ravaged by his own bombers.
The enemy tactics consisted of the use of 100-150 tanks on a front of one kilometre.
There were three waves, each with its own definite task: (1) Engaging with fire and destroying the sources of defence fire, especially of anti-armour weapons; (2) Penetrating deep into the defences, for the purpose of overpowering the artillery and reserves; (3) Consolidating the gain.
It was possible to include in the principles of defence outlined by the Polish Regulations of 1939 some instructions for dealing with such attacks and to state the complement of anti-armour weapons and units required by a division. The defence principles were, however, not fully applied.
5. The Equipment of Commands
The activity of the fast armoured-motorised divisions and of the air force increased the depth of the battle zone to such an extent that it covered practically the whole country. This fact rendered necessary a revision of the equipment and organisation of the higher commands. There were in Poland many cases of a disruption of liaison between higher commands, resulting in individual fighting on various sectors, which favoured the enemy. The wire communications failed frequently. There were not enough underground-cable connections for war purposes. The car proved to be too slow as a means of liaison, while the use of aeroplanes was difficult in view of the mastery of the air possessed by the enemy. Landing difficulties made aerial communication available only for the higher commands.
6. The Other Arms
The other arms served as the auxiliaries of the armoured and air forces which brought vitory to the Reich in its lightning war.
Artillery. -Germany devoted considerable attention to artillery, providing it liberally to divisions, though not nearly in quantities usual in the war of 1914-1918. There was a predominance of heavy, powerful weapons, mostly howitzers. The tactics of fire were based on concentrated hammerings and rapid support in action. Those were the points emphasised in the training and the instructions about the collaboration of different arms.
Infantry. - The role of [German] infantry was reduced to defence, taking over captured ground and fighting in collaboration with armoured units. There were a few battles of the old type, but they were generally concluded by bringing up the tanks and the air force. Up to that moment, however, they developed in a manner similar to that observed in previous wars. The intensity of machine-gun fire was carried to its highest pitch, in order to be used as an unfailing method of pinning the enemy down to the ground and paralysing his movements. The present organisation of infantry requires large quantities of special equipment, adapted to different conditions of the ground, various offensive weapons and methods of warfare. As this equipment has to be made reasonably secure against fire of normal intensity, it is to be feared that infantry must lose much of its former mobility. It is threatened with becoming simply an auxiliary service of various specialised arms. The Polish infantry frequently carried out bayonet attacks, displaying a moral and physical resistance and marching ability superior to that of the German infantry. Those assets should not be disregarded, and it is to be expected that infantry may be reorganised and adapted to the purposes of position warfare on the one hand, and of mobile fighting on the other. This would involve a different organisation of divisions.
Cavalry. - Although the Polish cavalry upheld its splendid tradition, and carried out faithfully its orders, it proved to be an expensive army, disappointing some of the hopes which were placed in its fighting value. Its speed sometimes proved very useful, but it was still too slow, and its fire power was inadequate for the carrying out of the duties which used to fall to its share under the old conditions. When technical equipment is insufficient, it still remains the fast arm.
Supplies and Transport. - The Polish campaign proved again what huge quantities of material have to be carried over large distances in a relatively short time under modern war conditions. Horse traction is out of the question under such circumstances. The numerous examples of the paralysing of the movement of divisions in the course of concentration and the technical difficulties occasioned by the handling of immensely long columns of traffic rule out the horse as a means of transport from the regiment upwards. The destruction of railway lines and the dangerous positions of junctions limit to some extent the efficiency of railway transport.
The present war requires motor transport capable of dealing with work under normal cross-country conditions.