TOP SECRET
Berlin, 25 August 1938
General Staff of the 5th Section (German Air Force)
(Genstb. 5. Abteilung)
No. 28/38. TOP SECRET (G-2)
For Commanders only [CHEF-SACHE]
THROUGH OFFICElR COURIER ONLY
Subject: Extended Case Green [GRUEN—code for Czechoslovakia.] Estimate of the Situation with Special Consideration of the Enemy.
A. Initial Political Situation:
1. The basic assumption is that France will declare war during the Case Green.
It is presumed that France will only decide upon war if active military assistance by Great Britain is definitely assured.
2. The Soviet Union will probably side immediately with the Western Powers.
3. It is not expected for the moment that other states will intervene against Germany.
The Dutch-Belgian area assumes in this connection much more importance for the prevention of the war in Western Europe
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than during the World War. This mainly as an advanced base for the air war.
4. The United States of America will immediately support the fight of the Western Powers with strong ideological and economic means.
5. Italy, Nationalistic-Spam, Hungary and Japan are regarded as benevolent neutrals.
B...Initial Military Situation:
1. The French-Czechoslovakian treaty provides for military
assistance only in the case of an unprovoked attack. At least an agreement of the French and British views as to the legal aspect has to be achieved. If only for political reasons we have to consider the 2nd day as the earliest possible day of war on a European scale. In cast of a 24 hour ultimatum it would be the 3rd day.
2. It is further assumed that the actual commencement of hostilities will only take place after the French armed forces have been tactically deployed. That means within the fourth to eighteenth day. This to
a. use the deployment as a means of political pressure,
b. and to be able to deploy the troops undisturbed.
3. The war aim of the Entente Powers is to be considered as the overcoming of Germany through attacking its war economy. With other words through a long war.
4. The following are possible methods of operation for the French army:
a. to man and hold the Maginot-line,
b. to march into Belgium and the Netherlands at the beginning of the war with the aim of occupying the Ruhr-territory.
All suppositions support the first alternative.
5. The French Air Force will probably attack both economic and German Air Force targets as well as military and communication objectives. Thus no concentrated effect will be achieved at any one place.
6. The French Navy will probably cooperate through operations with the British sea power to supplant the North Sea blockade. The aim will be the maintenance of naval predominance in the Atlantic and the Western Mediterranean.
7. The British Air Force is assumed to be committed from English bases against the Rhine-Westphalia industrial area and the North Sea ports. Sooner or later the Belgium-Dutch neutrality will be violated.
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A camouflaged aircraft reporting network in Belgium and the Netherlands has to be taken into account from the first day of the war. No transfer to France on the part of .the British Air Force need be expected at the beginning of the war. Equally it is held to be out of the question for any large parts of the British armed forces to be transferred to France.
8. Provision seems to have been made for the use of North French ground organizations during the course of the war at least by part of the attacking British Air Forces.
The existence of a relatively large number of civilian airfields in Belgium and the Netherlands seem to indicate the intention of moving advanced elements of the air defenses of London (light fighters and reconnaissance aircraft) into this area after a while.
9. Thanks to the expected neutrality of Poland, the active participation of Soviet Russia will be largely restricted to the prosecution of the war in the Baltic.
Furthermore, air attacks against East Prussia and the Baltic coast are to be anticipated and occasional raids on Berlin are regarded as possible.
10. The basic assumption in respect to our own prosecution of the war is that two war plane air forces will be available in the West at the beginning of hostilities. There will be five war plane air forces in all after three to four weeks. The aim will be to bring about a decision by the defeat of the Western powers.
C. Task of the German Air Force:
The German Air Force has at present not all the forces necessary to seek a decision by attacking the enemy's war economy with the aid of the navy. Thes.prime responsibility of the German Air Force in the present situation must be to help the armed forces immobilized opposite a fortified front to achieve operational freedom.
D. Enemy War Plane Forces:
1. The French Air Force will have on the 1st October some 640 war planes in the front line units on French home territory of which not more than 120 to 150 attain a modern standard of performance. Available reserves total about 320 obsolete war planes.
There are another 150 obsolete war planes in North Africa for use in colonial war or against Southern Italy.
It is assumed that the French home war plane units will be deployed for the most part in the known areas of Eastern France at the beginning of the war. They will be employed against various targets (air force targets, industrial and communications
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targets, military installations, Army targets) in the operational area as well as in depth according to the capabilities of their personnel and equipment.
Any transfer of more than insignificant forces to Czechoslovakia is regarded as outside the range of practical possibilities, as is the concentrated commitment of large formations against the armies fighting in Czechoslovakia.
2. The British war plane force will consist of some 850 war planes on October 1st of which 300 to 350 can be regarded as modern. The majority of the front line aircraft as well as some 200 to 300 reserve aircraft can be described as only conditionally serviceable in the face of modern defences.
Due to their inadequate range the present British war plane formations are not in a position to carry on a vigorous air war from their home bases only without violating sovereign Dutch or Belgian territory.
Even if Dutch and Belgian neutrality is jgnored only the modern war planes need to be taken into account as a serious threat to the Ruhr.
A transfer of British Air Forces to Northern France is to be expected at the earliest, after several weeks of war.
If the French Army Command decides to march through Belgium and the Netherlands the immediate influx of British fighters into this area becomes probable.
Heavy attacks against the North Sea ports by carrier based aircraft need not be reckoned with:
a. because the equipment and training of these aircraft is designed to fit them for specific naval tasks;
b. because aircraft carriers, due to their vulnerability, will be committed in the North Sea only for very pressing reasons, which do not exist in this instance.
On the other hand occasional attacks by. coastal aircraft forces against targets on the North Sea coast are feasible and probable.
E. Enemy Aircraft Industries:
1. The first aircraft put into mass production as a result of the expansion of French military aircraft industry during the years 1934 to 1938 are at present rolling off the assembly lines. At the moment the aero-engine factories are lagging behind with deliveries.
In August 1938 forty single-engined and thirty twin-engined military aircraft were delivered to the French Air Forces. It must be assumed that these figures will be increased during the coming months to 100 aircraft a month, 50 single-engined and 50 twin-engined.
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A further moderate increase in production is possible and to be expected from spring 1939 on.
2. In Great Britain existing plants have been extended since 1936 with the aid of State funds and the effect on the armament situation will begin to make itself felt increasingly from 1939 on. If the present plans will be observed the program will be completely carried out by 1941.
Present production (August 1938) is estimated at some 200 aircraft of all types (commercial and military aircraft) a month. It must be noted that the import of training aircraft and long-range reconnaissance aircraft from the United States and Canada is intended.
3. North American aircraft industry (United States and Canada) is at the moment fully occupied. No notable expansion has yet taken place but is possible. A possible expansion would have no practical effects in 1939.
250 aircraft of all types (commercial and military) a month for the home and foreign market may be stated as the present production rate. Appreciably more aircraft engines are manufactured.
F. Position with regard to preparation of target data:
1. It is proposed to supply units on or before 5th October with the following target data for France:
a. Air Force (airfields, air parks and equipment depots, air force fuel dumps). About 90% of existing installations are included.
b. Fuel Supply.
100% of the refineries are included and 60% of the total storage capacity (including the above-mentioned Air Force fuel dumps).
c. Ammunition Supply.
An estimated 70% to 80% of the total productive capacity of explosive and gunpowder factories and 17 large supply dumps (main ammunition depots and ammunition depots, Army and Air Force) are included.
d. Power Supply.
All the large power plants are included.
e. Key Industries.
In particular the Paris aero-engine industry has been included.
/. Targets in the Paris area.
Further target data, particularly for essential industrial targets, are accumulating currently.
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In addition, command authorities will receive maps of the tactical situation and of target groups on or before the above-mentioned date.
2. Basic target maps of British ground organization (airfields) are approximately 90% ready. They have been passed on to Air Force Group 2 for printing and for the adding of sectional excerpts of maps. They have been ordered to be ready by 15 September.
As far as essential industrial targets are concerned, work has been carried out on the food and crude oil supply systems and docks in the London and Hull areas (basic target maps, sector maps, partially covered also by aerial and ground panoramas).
These will be reproduced after the ground organization targets have been printed. They cannot be expected to be ready before 20 October.
Tactical maps and target maps of London and Hull will be issued to the command authorities prior to the end of September.
3. The basic target maps of tihe Air Force objectives for Belgium and the Netherlands are ready for printing. Reproduction and distribution (including sector maps) will probably be possible only during October.
4. In general it must be emphasized that, unlike Czechoslovakia, there are relatively very few aerial photographs of Western European targets available.
G. Recommendations for our own Prosecution of the Air War.
1. A negative answer must be given to the question as to whether it is appropriate to postpone the massed commitment of our striking power until the spring. The balance of force would probably have altered by that time to our disadvantage due to further progress of French and British aircraft industry and imports from North America.
2. From a climatological point of view the autumn offers our
forces greater prospect of success than the enemy, due to our relatively good training in instrument flying. .
B. As our forces must be regarded as small, even if we accept the figure of 5 air forces as a basis, the task can only be fulfilled by concentrated blows directed against the enemy's weakest points.
For this purpose choice of targets must be made with the greatest care and must be restricted to the decisive points.
4. As long as only 2 air forces are available prosecution of the war on the basis of gaining time is advisable. This is seen in
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attacks against the enemy air forces in the airfields where they are deployed in Eastern France, with a view to prevent complete aerial predominance By the enemy.
Attacks on Paris should only be carried out as a reprisal, especially as the air defences in and around Paris are strong. Such attacks must however be possible at all times.
Direct cooperation with the Army is only considered desirable if the enemy deploys or advances in such strength as to endanger the Western German fortifications by a break through or outflanking.
Support for the Army will be supplied in this case by attacks:
a. against transports, troop concentrations and movements,
b. against enemy war planes, should these cooperate with his armed forces in great numbers.
Should there be danger of a penetration of the Western fortifications, a further measure would be to concentrate fighter forces scattered in the West on the decisive ground front.
Attacks against objectives in the British Isles are to be regarded as unjustifiable in view of the small numbers of our combat forces.
Should the enemy remain on the defensive in the ground war and withdraw with his war plane forces to the West there will be no urgent reason for us to commit our own forces. In this case it would seem better to save our forces until reinforcements arrive.
5. As soon as strong forces are freed for the prosecution of the war in the West, operations in the air must be directed without delay at reaching a decision.
It would seem possible to achieve this end by attacking:
a. fuel refineries and dumps;
b. gunpowder and high explosive factories, main ammunition depots and ammunition depots;
c. the most important parks handling imports which are also centers for the transfer and reshipment of fuel and ammunition.
Thus the enemy's fuel and ammunition supply system for his ground and air forces would be paralyzed or at least curtailed to an intolerable degree.
Assuming that the individual groups of targets are one after the other successively attacked until eliminated it would appear that by the use of 5 air forces a sufficient measure of success
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could be achieved to enable the Army to break through the enemy's fortified front.
No large-scale operations against targets in the British Isles could be carried out in addition to this task.
Everything should however be prepared to make reprisal attacks against London possible at any time.
Considering the strength of the air defences in and around London success in such attacks is only likely if strong forces are committed.
In addition occasional harassing attacks against targets in South and Southeast England may be worthy of consideration, particularly if the weather enforces a lull in France. A. secondary aim of such attacks would be to pin down strong defence forces in Great Britain.
6. Should still stronger war plane forces—at least 3 air forces —be available after the french targets had been successfully attacked, they might be committed to advantage in attacks against the food supply of Great Britain, notably of London. It must however be emphasized that it is only regarded as possible to achieve decisive successes if considerably stronger forces are committed and if the western ports are also subjected to air attacks.
H. Requests to Armed Forces Supreme Command, Army and Navy:
I. The use of the Condor Legion against the refineries in Bordeaux and possibly against those in Marseilles would valuably supplement our attacks of the French fuel supply system.
2. The ammunition situation has to be rendered precarious for the enemy as soon as possible. Therefore the armed forces should accompany the air attacks against the ammunition supplies with synchronized offensive thrusts. Special attention should be directed towards the ammunition supplies stored in the Maginot Line itself and accessible to air attack.
3. The Navy should hamper imports through the French Atlantic ports to as great an extent as is compatible with its other tasks and the forces available. Especially for some 2-3 months at the beginning of the attack against the fuel supply of France.
4. Belgium and the Netherlands would, in German hands, rep-present an extraordinary advantage in the prosecution of the air war against Great Britain as well as against France. Therefore it is held to be essential to obtain the opinion of the Army as to
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the conditions under which an occupation of this area could be carried out and how long it would take. In this case it would be necessary to reassess the commitment against Great Britain.
Signed: For: WOLTER
1 inclosure '
Distribution:
Chief of German Air Force Operations Staff General Staff/5th Section (Draft)
1. copy with 1 inclosure
2. copy with 1 inclosure