Under the Spreading Chestnut Tree:
The Evolving Soviet-German Relationship in 1939
The short answer to the question as framed, seems to be that there is no known specific documented evidence of what the Germans planned to do in Poland in the absence of an agreement with the Soviet Union. The following quote from historian Norman Rich examines the significance of the Molotov-Ribbentrop Pact in Hitler's decision to go to war in 1939:
"Another possible explanation of Hitler's decision to go to war in
September 1939 was his success in arranging a nonaggression pact with
the Soviet Union on August 23, which, by freeing him from the danger
of a major war on two fronts, gave him what amounted to a blank check
for waging war against the West. Further, the economic agreements
concluded with the Soviet Union in conjunction with the nonaggression
pact assured Germany of vital supplies of strategic raw materials and
would go far to free Germany from the throttling effect of an Allied
The treaties with Russia, however, do not appear to have had any more
influence in fixing Hitler's decision to go to war with Poland than
the Anglo-French guarantees. Neither the Germans nor the Western
powers had any high regard for Russia's military capacity, which
appeared to have been eroded still further by recent large-scale
purges of the Soviet military leadership. Indeed British and French
lack of confidence in the effectiveness of Russia's military
co-operation was one of the major reasons for their lack of enthusiasm
for an alliance with Russia. As for Hitler, Russia played a remarkably
small role in his political and military calculations as he
contemplated the prospect of war in 1938 and 1939, and there is every
reason to believe that he would have resorted to military action even
without the Russian treaty. In both the Austrian and Sudeten crises,
while Russia was still openly hostile to Germany, Hitler had hoped and
expected his opponents to give way, but in each case he seems to have
been prepared to fight." (Rich, p.125)
Rich cites evidence that German intelligence had been monitoring British and French assessments of Soviet military capability during their negotiations with the Soviet Union between March and July 1939, and German archives contained files which included analysis by Allied military experts of the Soviet Army and Air force, and both were considered to be "very weak indeed", with "no ability to maintain an effective offensive", and British Foreign Office advice stating that "it was unlikely that on land [Soviet] military effort would be of very much effect". (Rich, p.293)
"Not until the first part of August 1939 is there reliable evidence
that Hitler had definitely decided to attack Poland. At this time the
Russo-German pact had not yet been concluded, nor had Hitler succeeded
in neutralizing the Western powers. Important as the negotiations with
Russia appear to have been in retrospect, Hitler seems to have
attached far more importance to his efforts to isolate Poland from the
West." (Rich, p.126)
Halder's War Journal on 14 August 1939 reports on a meeting between Hitler and his high command on that date and contains a number of relevant comments, which also serve as a very useful springboard for further exploring the issue of German considerations of the Soviet Union in her policy towards Poland in the pre-war period.
"Russia is not in the least disposed to pull chestnuts out of the
fire. Has nothing to gain, but much to fear, War at the periphery not
opposed to, perhaps even welcome, Not so in center, losing a war is
as much of a threat to the Russian state as a victorious army,
Interested in disruption of Western nations, access to Baltic."
(Halder, Vol. I, p.7)
"The last weeks have brought increasing conviction of Poland's isolation."
"Primary prerequisite: Clearcut military decision must be achieved
within measurable time. [Hitler] would expect Poland to collapse within a
week or two. Final disposition might take longer."
"Second prerequisite: Resolution to fight every comer. Build-up in
West must be completed to last detail."
"Relations with Russia: -- Loose contact, starting out from
negotiations for trade agreement. Still under advisement whether a
negotiator should go to Moscow, and, whether or not this should be a
prominent figure. Russia does not feel under any obligation toward
the West. Russians are sympathetic to dismemberment of Poland, On
subject of Ukraine, promise has been given regarding delimitation of
Spheres of Interest. -- Baltic States? The issue is Lithuania (not
the Baltic States). Russians want to discuss subject more closely.
Distrust. Want no common frontier. -- Fuehrer inclined to meet
It is clear that Hitler was determined to "fight every comer", although his contingency planning emphasis is clearly directed solely towards the possibility that Britain might fight, and that in such a case, the French would reluctantly join them. Halder's diary contains detailed descriptions of German military preparations in the West, and concludes that the limited time frame for a response will ensure that any Western intervention would be limited to basic mobilization plans, and German defensive requirements are meticulously calculated accordingly. There are no further operational plans for war with the West. As such it is not surprising to find no operational plans for the contingency of a hostile Soviet intervention either. The bulk of the German Army was already deployed in the East for operations in Poland, and in the presumed unlikely event of a surprise Soviet response, adequate forces to restore the situation would already be in place, and a major reassessment of the entire German war strategy on both fronts would be in order, before any offensive possibilities against the Soviet Union could be considered.
Given Rich's claim that the Russo-German pact had little impact on Hitler's decision for war in 1939, it is worth taking a few steps back, and looking at the evolution of German policy towards Poland in the post-Munich period, to see if any conclusions can be reached about how the Soviet Union actually figured into German decision making during that time.
Shortly after Munich, both Hitler and Ribbentrop made friendly advances towards Poland, offering new security guarantees in exchange for German acquisition of Danzig, and transit rights across the Polish Corridor. Hitler claimed a strong Poland in the East eased his own security concerns, and even hinted that their mutual opposition to Russia offered the possibility of future territorial expansion for Poland into the Ukraine (should the opportunity arise). His strategic outlook, at this time, was characterized by his belief that the West needed to be dealt with as the first military priority, and a friendly Poland in the East would secure his rear against a two-front war.
By January 1939, Germany's friendly policy towards Poland had broken down. German proposals had been repeatedly rejected, as Poland correctly determined that moving too closely to Germany would be seen as hostile by Russia, and this would destroy its ability to maintain its independence by balancing its relations with both Germany and Russia, and would result in Poland becoming a dependent vassal of Germany. Hitler concluded that this same attitude would also inevitably prevent Poland from accepting assistance from Russia, in the event that he adopted a more confrontational approach towards Poland.
On 12 February 1939, Hitler met with Slovak dissidents and set the wheels in motion for the dissolution of the rump Czecho-Slovakian state, by stating his support for Slovakian independence. A political crisis ensued in that country, which by early March 1939 had reached a culminating point.
On 10 March 1939, at the height of the rising tensions in Czecho-Slovakia, Joseph Stalin gave a speech to the 18th Party Congress, which was widely seen as having major political significance. He denounced the unwillingness of the West to fully involve the Soviet Union in its collective security arrangements, and claimed the West was insincere, and was actually intent on dragging the Soviet Union alone into war with Germany. He declared that the Soviet Union had no reason for hostility towards Germany, and in fact saw prospects for enhanced economic engagement. He believed Germany would be crazy to try to take the Ukraine from the Soviet Union, as Western propaganda was suggesting, because the Soviets could and would defend their own interests vigorously, but he had no intention of pulling other's chestnuts out of the fire.
This speech by Stalin was understood as a declaration that the Soviet Union had lost faith in the Western efforts of collective security and would not involve itself further in confronting Germany unless their own interests were directly threatened. The reference to "chestnuts" in subsequent speeches by Hitler, and in Halder's diary, clearly shows the significance with which the Germans held this speech as an indicator of Soviet intent.
The following day, on 11 March 1939, Hitler ordered the preparation of an ultimatum to the Czech government, he presented a verbal ultimatum to the Slovakians on 13 March 1939 to enact their declaration of independence, and by 15 March 1939, Czecho-Slovakia had ceased to exist and was under German domination. The brutality of the dismemberment was later said to have been intended as a demonstration to the Poles, and the diplomatic fall-out was immediate, with Britain and France offering military guarantees to Poland, Romania, Greece, and Turkey, the effect of which was to stiffen Polish resolve and end any possibility of an amicable resolution of the German demands over Danzig and the Polish Corridor.
By 30 March 1939, when Hitler was finalizing his annexation of the Memel territory from Lithuania, he claimed he had come to the realization that Poland was too untrustworthy to
rely upon in the German rear while war with the West was on the horizon. He reversed his previous policy and determined that Poland would need to be dealt with first, before Germany turned West. The formalization of the Memel transfer included a nonaggression pact between Germany and Lithuania, and a provision that neither party would allow a third-party to attack the other from its territory, a clear sign that Hitler's eyes were now turning pointedly towards Poland and the Soviet Union.
Just a few days later, on 3 April 1939 the Fall Weiss directive was drafted. It was formally issued on 11 April 1939. Norman Rich indicates that the wording of the directive was identical to earlier directives which had been issued before the annexations of Austria and the Sudetenland, and gave clear preference to a peaceful resolution, so his opinion is that war between Germany and Poland was not inevitable at this point, but clearly the changing attitudes of the Western powers had shifted the political climate dramatically. It is interesting to note, that the Baltic States were included along with Poland as the subjects of the Fall Weiss directive, and it was anticipated that they would submit to German military demands, resulting in Germany occupying territory up to the "old Courland line". Preparation of Fall Weiss was completed by 15 June 1939.
On 3 May 1939 Molotov replaced Litvinov as the Foreign Minister of the Soviet Union, which Hitler interpreted as an end to the Soviet "era of intervention".
On 23 May 1939, Hitler gave a brutal speech to his generals, which some have suggested left no room for any peaceful resolution of the Polish situation, although Norman Rich suggests the reporting of this speech is not entirely reliable, and prefers a later date in mid August when he believes all hope of another bloodless diplomatic coup was truly lost.
Which brings us back to Halder's diary on 14 August 1939, a week before the Molotov-Ribbentrop Pact was signed. He claims that by that date, the Soviets had already indicated their support of the partition of Poland. They had already agreed to spheres of influence, which had curtailed German ambitions in the Baltic States. They wanted Polish Ukraine, but did not want a common frontier with Germany, and there were unresolved issues with Polish Lithuania. Hitler preferred to meet the Soviets halfway. History shows us that even after the Molotov-Ribbentrop Pact, these issues had not been fully resolved, and indeed adjustments were made to the delineation of spheres of interest while the military campaign was underway.
It is quite evident, that the Molotov-Ribbentrop Pact was not in itself, the decisive moment in time it is usually held to be. German and Soviet relations were clearly evolving throughout 1939, and German policy towards Poland was evolving in tandem. If a decisive moment is sought, it seems to me to have been closer to the 10 March 1939, when Stalin made his "chestnuts" speech in Moscow. From that point on, there was little consideration given at all to the possibility that the Soviet Union would interfere, or intervene, to halt German encroachments on Poland, and indeed it was a sign for Germany that Russia would entertain improved relations at the expense of the duplicitous Western warmongers and their allies. The dramatic shift in the diplomatic scene in the days which followed, seems to support this view. As such the subsequent military planning, including Fall Weiss, can be seen as arising entirely within the era of Soviet-German harmony, and the question of military contingency planning towards Russia becomes somewhat redundant.
References (more to follow)
Hitler's War Aims: Ideology, the Nazi State, and the Course of Expansion (1973) - Norman Rich
War Journal of Franz Halder - Franz Halder
Letter Reporting on Stalin's Speech of 10 March 1939 - The Chargé in the Soviet Union (Kirk) to the Secretary of State