The Finland-Swedish historian and architect Carl O. Nordling (1919-2007) reconstructed Stalin's speech to the Politburo of August 19, 1939 from texts published in Novy Mir (Moscow) and Revue de Droit International (Geneva). An excerpt (the bold text appears in both versions, the normal text only in Novy Mir and the italicized text only in Revue de Droit International):
The question of war and peace has entered a critical phase for us. Its solution depends entirely on the position which will be taken by the Soviet Union. We are absolutely convinced that if we conclude a mutual assistance pact with France and Great Britain, Germany will back off from Poland and seek a modus vivendi with the Western Powers. War would be avoided, but further events could prove dangerous for the USSR.
On the other hand, if we accept Germany's proposal, that you know, and conclude a non-aggression pact with her, she will certainly invade Poland, and the intervention of France and England is then unavoidable. Western Europe would be subjected to serious upheavals and disorder. In this case we will have a great opportunity to stay out of the conflict, and we could plan the opportune time for us to enter the war.
The experience of the last 20 years has shown that in peacetime the Communist movement is never strong enough for the Bolshevik Party to seize power. The dictatorship of such a Party will only become possible as the result of a major war.
Our choice is clear. We must accept the German proposal and, with a refusal, politely send the Anglo-French mission home.
It is not difficult to envisage the importance which we would obtain in this way of proceeding. It is obvious, for us, that Poland will be destroyed even before England and France are able to come to her assistance. In this case Germany will cede to us a part of Poland… Our immediate advantage will be to take Poland all the way to the gates of Warsaw, as well as Ukrainian Galicia.
Germany grants us full freedom of action in the Pribaltic/three Baltic States and recognizes our claim on Bessarabia. She is prepared to acknowledge our interests in Romania Bulgaria and Hungary.
Yugoslavia remains an open question, the solution of which depends on the position taken by Italy. If Italy remains at the sides of Germany, then the latter will require that Yugoslavia be understood as her zone of influence, and it is also by Yugoslavia that she will obtain access to the Adriatic Sea. But if Italy does not go with Germany, then the latter will depend on Italy for her access to the Adriatic Sea, and in this case Yugoslavia will pass into our sphere of influence.
This in case that Germany would emerge victorious from the war. We must, however, envisage the possibilities that will result from the defeat as well as from the victory of Germany. In case of her defeat, a Sovietization of Germany will unavoidably occur and a Communist government will be created. We should not forget that a Sovietized Germany would bring about great danger, if this Sovietization is the result of German defeat in a transient war. England and France will still be strong enough to seize Berlin and to destroy a Soviet Germany. We would be unable to come effectually to her assistance/to the aid of our Bolshevik comrades in Germany.
Therefore, our goal is that Germany should carry out the war as long as possible so that England and France grow weary and become exhausted to such a degree that they are no longer in a position to put down a Sovietized Germany.
Read it all.
(Hat tip: Mari-Ann Kelam)