What are the reasons and consequences of signing a non-aggression pact with Germany?

We are talking about the events of August 1939, the reasons for signing the pact were as follows:

The failure of an attempt to create a collective security system in Europe in 1938 because of the Anschluss of Austria and the partition of Czechoslovakia with the consent of England and France.
The failure of negotiations with the French delegation in July 1939, they did not want to sign anything, as subsequent events showed, they did not want to help Poland in September 1939.
Fights on the Khalkhin-Gol river with the Japanese. It was necessary to secure the country in the east.
The need for trade with Germany.

Consequences:

Japan stopped its aggression in the Far East.
The USSR resumed purchases of machine tools and engineering products in Germany.
The USSR received the opportunity, in the event of a German attack on Poland, to send troops into the territory east of the Curzon line and take back the lands that it gave to Poland in 1921.