What does "selling the timber" mean in Animal Farm?
In Animal Farm, the selling of the timber is symbolic of the Nazi-Soviet Nonaggression Pact of 1939. Under the terms of this pact, the Nazis, under Adolf Hitler, and Joseph Stalin's Soviet Union promised to not attack each other and to equally divide Poland, a country which Germany was about to attack. The pact was signed on August 23 1939 but was broken by Hitler in June 1941 when he invaded Russia as part of his Operation Barbarossa.
The signing of this pact is reflected in Chapter Eight of Animal Farm when Napoleon (representative of Stalin) and Mr. Fredrick (representative of Hitler) strike a deal over the timber. Just like Hitler, however, Mr. Frederick deceives Napoleon by giving him fake bank notes which is reminiscent of Hitler's breaking of the pact. Similarly, the conflict which ensues between Napoleon and Frederick is very similar to the real fighting which took place between the Germans and the Russians in World War Two.
For more information on this pact, please see the first reference link.