In 1922 a parliamentary investigation was done in the Reichstag on the causes of the collapse of the 1918 offensive.
Several reports were written for the parliamentary commission. They were published in book form with the title 'Ursachen des Zusammenbruchs Enstehung,Durchführung und Zusammenbruch der Offensive von 1918'
Here follow some extracts from the report by Gen. von Kuhl.
" I. Replenishment and supply of the army
In the fall of 1917 the war ministry judged the expected replacement situation in 1918 as follows: The monthly need is estimated at 160.000 men. With inclusion of those born in 1900(200.000 men) and monthly 60.000 convalesced men, with use of Gv men( suitable for garrison duty)to replace commandered kv men(suitable for war duty) in the troop units(300.000 men) and the employment of 200.000 deferred men, the replacements are sufficient until july 1918. From then on only 60.000 convalesced men are monthly available. Because the stock in the replacement batallions and the field recruit depots which could not be stated , was not counted, it was assumed that the replacement could be covered until september 1918. What was lacking needed to be covered by deferred men and older conscripts.
A new calculation of 17 december 1917 used some different numbers, in that those born in 1900 was counted as 250.000 men and the monthly need was estimated at 150.000 men. This still resulted in a lack of 354.000 men for 1918, although replacement batallions and field recruit depots were counted.
The birth year 1898 had already been employed in 1917 . The birth year 1899 was partially in the recuit depots in the east, partially in the replacement units in Germany, for a smaller part(the physically and mentally most mature) in the field recruit depots in the west.
In the opinion of the OHL this birth year was not yet ready for the demands of the fighting in the west. The birth year 1900 could at the earliest be employed in the late fall 1918.
One had already anticipated far with the employment of the 18 year old recruits of the birth year 1899.
The OHL was therefore , before the start of 1918, informed of the difficulty of the replacements situation. .....
The OHL planned to employ 140.000-150.000 men of the recruit year 1899 in the recruit depots in the east. The commander in chief East should give a corresponding number of kv men in the age group of 20-35 to the west. The commander in chief East answered in a letter of 13 october 1917 which gives an insight in the conditions in the east. It says in this: " In the total combat strength of the front of 492.000 men(527.000 minius 37.000 gv) are comprised 85.000 men from the Alsace-Lorraine, around 17,5 percent. The transfer of 150.000 men of birth year 1899 would make up 30,5 percent of the beforementioned combat strength. After the putting into execution of these measures 48 percent of the whole front or around half would consist of men which more or less could only face combat under supervision and support by the other half. When one now takes into account that also this trustworthy half of the men for a large percentage consists of older men because only the best men in the age of 20-35 should be given to the west, then there must be reservations whether the absolutely necessary supervision of the untrustworthy elements for guard duty and combat is possible by the others, particularly because this supervision of man to man is made much more difficult by the extension of the combat sector. It is requested not to transfer to the command area more than 100.000 men of the birth year 1899." The OHL agreed with this. 30. 000-40.000 men of the birth year 99 , the strongest men with solid character would be employed in the recruit depot depots in the west. However, the war Ministry only made available 107.000 men because otherwise there would be no kv men in the home country. The War Ministry wanted to send a further 40.000 men in the field in february if the chief of the general staff was willing " in case of necessity to make available complete units of the field army for the eventuality of inner disturbances(War Ministry 10 january 1918)."
The OHL drew everything which could be used from the recruit depots of the east. .....
Releases of kv men under 35, no Alsace-Lorraine men, were ordered: in september first 4500,then 1500, in october 2000.
Commander in chief East reported in october that there were no more men suitable for the west in the recruit depots. 4000 men had already needed to be withdrawn from the front(18 october 1917).
It is to be taken into account concerning these releases that the divisions destined for use on the western front first had to be filled up from the recruit depots....... All men from Alsace-Lorraine and all men not suited for the western front in these divisions had to be exchanged for usable men from the divisions that stayed behind. The recruits of the birth year 99 which were transferred to the recruit depots in the east could not be used in the front but each division which went to the west had to be given a recruit depot of 600 men.
After the mass of the divisions to be transferred to the west had been transported, the commander in chief East reported to the OHL on 23 may 1918 that the individual armies had only weak redruit depots and that no men were available anymore which were suitable for the west and that the divisions in the east were for the largest part composed of 40 year olds.. Neverthelless, from may until the end of the war ten more divisions were withdrawn from the eastern front......
In may 1918 the field strengths of the east army were further generally reduced , to again free men, which were destined to replace all kv men still available in the rear in the west or in economical enterprises. The measure was executed although the Armygroup Eichhorn with reference to the situation in the Ukraine had urgently requested to desist from it. This way 43.000 men were gained.
In july 1918 a reducing of the field strength of the Landsturm batallions in the east was used to replaced the kv men taken from the special units( air, signal, transport,....).
At the end of august, the commander in chief East was asked by the OHL if with the severe lack of men, he could still help the west in some way. Again, the strengths of the batallions of the whole east front were reduced by 50 men(to 600)."