Fall 1939

[joegrundman]

Germany declares war on Poland
Great Britain and France declare war on Germany
Japan is at war with China

A German diplomatic mission to Ireland on the eve of war fails to get any result. The Irish appreciating the coming war and remembering the events of 1917, feel no need to risk the ire of Britain, and vow to stay strictly neutral for the course of these hostilities.

[Oberon]

The Battle of the Atlantic gets off to a blistering start with Uboats and Raiders accounting for six transports, four sunk, two damaged for no losses to the Kriegsmarine.
Churchill is furious, Raeder is ecstatic.

[JALU3]

US Merchant Marine Vessels start painting large letters on the side of their hulls.

Unions warn US based mariners to only accept assignments on neutral flagged merchant vessels, or face getting caught in another one of Old Europe's wars.

[joegrundman]

Unternehmen Fall Weiss


Case Study: The first blitzkrieg – Germany demonstrates modern combined arms warfare in Poland.


Introduction to Twentieth Century Corp-Level Operations


Sandhurst 1957


The German attack on Poland in September of 1939 is an interesting case study in modern combined arms operations since it shares many of the characteristics of the larger attacks on France and Russia, and later by all forces in World War II.


In contrast to most other armies who never took massed armoured warfare much beyond the theoretical level in the inter-war years, the German armed forces developed a principle of using all mechanised forces to spring from a breakthrough in the front line without regard to it's flanks, and use mobility and hitting power to surprise formations behind the frontline, seize valuable objectives before they could be reinforced, and cut supply to large frontline units, allowing following infantry to overwhelm the isolated frontline units easily.


Massed air support was used to hinder the movement of reinforcements by striking bridges, railheads and junctions, oil and ammunition dumps as well as troop concentrations. Therefore, air superiority was a prerequisite for this kind of warfare that has become known as Blitzkrieg, lightning war.





Although numerically strong the Polish infantry was poorly equipped in comparison to the Germans, and a failed Polish counterattack featured a horseback attack. Polish units lacked machineguns, heavy weapons, command and control, and support vehicles.


German panzer forces consisted of 3,000 panzers massed into four corps. In contrast, the poles had some 800 tanks varying from about 100 modern tanks, 500 tankettes and 200 First world war french Renault FT17s distributed evenly throughout the infantry as a source of mobile infantry support. They proved ineffective in this role, although it is well known that British and French forces failed to appreciate this at the time. Two German panzer corps (4o6) were attached to Army Group North, and stationed in East Prussia, the other two were attached to Army group South and stationed in occupied Czechoslovakia, just south of Krakow.


In air forces the difference was also very great. The Luftwaffe at the time was the most modern and capable air force of all the major powers, with about 2,000 modern warplanes, grouped into 20 large formations (AAF), half around Breslau, a quarter in Kolberg and a quarter in Konigsberg.


Polish air forces amounted to some 400 aircraft of widely varying quality. The P-11 was the best Polish fighter and did represent some threat to Luftwaffe bombers. In effect the Polish air forces amounted to two factors, one based around Warsaw and the other based around Brest-Litovsk.


The dotted line on the map represents the line of demarcation from the Pact known either as the Molotov-Ribbentrop Pact, or the Nazi-Soviet Pact. The agreement stipulated that all lands East of this line would be taken by the USSR, that to the west by Germany.


According to the treaty German forces may only cross this line as part of an attack on Poland, but must redeploy to the German side immediately after the attack is finished:

1. 1. 64.34 FALL 1939 GERMAN OCCUPATION PROHIBITED: In Fall 1939, German units may move across the partition line into eastern Poland to facilitate the German attack on Poland, but German units may not remain in eastern Poland at the end of the Axis player turn. Compliance with this restriction may require the voluntary elimination of German units (28.91). Incursions into eastern Poland during the Axis Fall 1939 player turn do not give Germany control of any eastern Polish hexes or affect the RGT level.

The Polish placed their main defense in Warsaw and the second strongest troop concentration in the key area marked on the map as N35.

[joegrundman]

The first shots are fired.


The Blitzkrieg attack depends heavily on Luftwaffe AAF flying ground support to prevent movement of reinforcements. This requires air superiority so accordingly among the very first actions of the war were Luftwaffe Counter-Air missions to neutralise the Polish airforces in Warsaw and Brest-Litovsk.


The Germans calculated very carefully how much force to devote to this mission in order to maximise the airforces that would remain available for ground support operations.





The modernity of the German forces (air nationality modifier2) versus the Poles (air nationality mod 0) meant that only 1 AAF was needed for each Polish AAF. The +2 modifier guaranteed that 1 German AAF would at least invert the polish air force, rendering it unable to fly defensive ground support. In the following table, with 2 dice and +2 mod, the lowest roll from 1 AAF = 4, which here gives a result of 0/1. the number after the slash is the number of opposing AAF that have been inverted (neutralised), the number before is how many destroyed. In contrast for Poland to destroy a german AAF at -2 mod requires a natural roll of 8. But even so, the Polish airforces will be neutralised.





In fact despite being outclassed, the Polish airforce fought with distinction, downing a large number of German planes. Nonetheless the Polish air force was unable to provide any ground support in the following battles


Germany loses 2 AAF

[joegrundman]

The Wehrmacht moves in.


It's important to understand the two cycles of ground movement and attack.

The first cycle uses all infantry and armour units, and if a breakthrough is made, the second cycle only uses armour units. This is the exploitation attack. Armour units that exploit may have already moved in ground movement phase, but they may not have already attacked.

Armour units that will exploit must start the exploitation phase adjacent to the units that will make the breakthrough, so forward planning is necessary..

Making a breakthrough also must take one armour unit (typically only 1 armour unit, and infantry makes up the numbers since one normally wants to reserve the maximum number of armour units for exploitation.


Since Germany has four Panzer corps and one is needed to make a breakthrough, there are three Panzer corps to exploit with.


Movement




The three infantry corps from Army Group North swung down and in to East Poland in order to attack the Polish infantry directly east of Warsaw. Total attack = 9 vs defense 2 = 4:1. Defenders generally have a defensive modifier (DM) of at least 2 as a bonus for defending. This means the total defense is 2 times the printed strength. In this case the printed strength is 1 so with DM2, the total defense is 2.


Two infantry corps and one panzer corps from Army Group South move up into Southern Poland to attack the southernmost Polish infantry. Total attack = 10 vs defense 2 = 5:1


Preparing the exploitation force


The careful planning of the German general staff was apparent with the dramatic moves to assemble the exploitation force in the area of the intended breakthrough in South Poland.


The two panzer corps from Army Group North raced south to tuck in behind the attacking force near Krakow, and joining it the last Panzer corps coming north.




The first attacks are made.


Both attacks automatically succeed, as the combat results table shows:




The infantry attack to the East of Poland is at 4:1 (three 3-3 inf vs a 1-3 polish defense. Defense mod = 2, so the attack is 9:2 = 4:1. The worst case is a roll of 1, an Ex-1 result. The Polish unit is eliminated, the germans lose 1 factor)


The breakthrough attack in the south is at 5:1 (two 3-3 and a 4o6 = 10, vs 1-3 DM2 = 10:2 = 5:1. The Germans cannot take damage since the worst result is Ex-2. Since the DM is only 2, this means the germans lose the defense strength x0, which therefore equals zero)


The German armour unit in the southern ground attack moves onto the vanquished hex and creates a breakthrough. However the infantry in the East attack near Warsaw do not enter the hex for reasons that later become clear.


rolling a 5 for the attack on M36 (east of warsaw) at 4:1 gets a D result. D = defender eliminated, attacker takes no losses.
rolling a 1 for the attack on O35 (south poland) at 5:1 gets an Ex-2 result. This means exchange at the strength of the defense with a defensive modifier of -2. At present the defenders have a DM of 2. 2-2 = 0. So the Polish force is eliminated and the Germans take 1x0 = 0 losses.

[joegrundman]

Exploitation

The three panzer corps in the exploitation reserve move onto the breakthrough on O35





In order for the armor on the breakthrough hex to reach Warsaw, they have to get through the three Polish infantry factors on N35 .


So the Germans had to overrun it, since units cannot otherwise make multiple attacks. If an attack is utterly overwhelming, at 6:1 odds, the units can overrun and continue moving and attack again.


An overrun can only use a maximum of two ground units, in this case, two Panzer corps attacking out of the breakthrough.


However because the infantry in N35 is in the open, it gets a -1DM

1. 1. 15.33 NEGATIVE DMs: Ground units are subject to a negative DM as follows:
      A. Infantry, replacements and partisans attacked by exploiting armor, unless defending in a capital, objective hex, IC, bridgehead or railhead. Airborne, marine, commando, Chindit and armor units (subject to 15.331) are not subject to this -1 DM when attacked by exploiting armor.

This -1 DM negates the normal +1 DM for defending. So the total defense of N35 is simply the printed unit strength, 3.


To overrun this hex requires 18 factors since 18:3 = 6:1. With two panzer corps providing 8 factors, 10 AAF fly out from Breslau to raise the total to 18.




Normally an overrun rolls 1 die. On a 1 the attacker takes a full Ex result, which in this case would be 3 factors. However, in the early war (until after the second turn after a western front offensive) Germany gets a surprise blitzkrieg advantage. Ex results are transferred to Ex-1. Since the DM of the defenders here is only 1 in the first place, it means no damage can be taken by germany.

[joegrundman]

Assault on Warsaw

Because of the restriction of only two ground units per hex, and the desire to have all three exploiting panzer corps attacking Warsaw, one armour unit moves into the now vacant hex east of Warsaw that was cleared in the earlier attack, while the third armour unit moves up next to Warsaw from the breakthrough. All three exploiting panzer corps are facing Warsaw.


The defense of Warsaw is 8 (it's a capital city so exploiting armour doesn't have the -1 DM bonus)




The three panzer corps strength totals 12. With the addition of 8 AAF from Kolberg and Konigsberg, the German attack = 20.


20:8 = 2.5:1


Because germany has a Combat Training Level of 2, and is therefore entitled to make a second attempt if the first is indecisive, 2.5:1 is enough to guarantee success.


Why? The first attack is at 2:1. The worst result, on a 1, is an 'a' result, the attacker loses half the strength of the defender. In this case the defender has strength 8, so the attacker loses 4.


20-4 = 16 and so Germany still has the strength to attack again at 2:1. But in a second attack, Germany has a +1 modifier, so now the minimum result is an Ex result, and so the attack, although potentially costly, is guaranteed to succeed.


Warsaw falls, with 100% certainty.




in fact germany rolled a 3. on the 2:1 of the combat result table is an Ex-1 result. Since the defense of Warsaw is 4 factors with a DM of 2 = 8, the Ex-1 means the Germans take the equivalent of 4 factors with DM 1 = 4.

A complete Panzer corps is lost in the attack.

Poland collapses.

Total German losses = 4o6, 2 AAF

replacement cost of 4o6 = 8 brps
replacement cost of AAF = 3 brps each
total replacement cost = 14 brps.

More costly than average for this attack due to the die rolls.

Poland surrenders. Neutral Minor Countries surrender at the end of the combat phase in which they lose control of their capital city. They do not have a turn to try to recapture.

According to the provisions of the Molotov-Ribbentrop Pact, any German forces now in East Poland must redeploy to the west of the pact line


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Note the effective use of all 20 German AAF. 2 counteraired the Poles, 10 supported the Overrun in N35, and 8 assisted the assault on Warsaw