Why was Animal Farm not an initial success in Britain?
As a critic of the Stalin regime, Orwell deplored both the horrors inflicted by British industrialization and Russian communist oppression. He feared a new, dawning age of totalitarianism on a global scale, where rebellion would be futile. As such, his writings reflected his belief that the right to morally inspired insurrection and civil disobedience must be preserved at all costs.
Orwell found great difficulty in publishing his novel during World War II, for the simple reason that publishers were skittish about being linked to literature which was a thinly veiled criticism of Britain's ally. Orwell wrote Animal Farm between 1943 and 1944, around the time that the Soviets were emerging as key players in the fight against the Germans. Orwell's disillusionment with the alliance between Stalin, Churchill, and Roosevelt is characterized towards the end of the novel when both men and pigs sit down to deliberate and debate new policies for governance. In the end, the pigs are indistinguishable from the farmers; the irony is that the oppressed have taken the place of the previous oppressors.
Orwell's criticism of Stalinist show-trials and the brutal Russian purges did him no favors. No publisher of any political persuasion dared to publish such literature critical of the fragile wartime link between England and the Soviet Union. Additionally, Orwell's support for Trotsky didn't help matters. Trotsky was to have been the natural successor to Lenin, but Stalin's hubris tolerated no competitors. He viewed Trotsky as a threat. His show trials implicated Trotsky supporters and Trotsky himself was eventually banished from the Soviet Union.
Eventually, Frederic Warburg published the first edition of Animal Farm in 1945, one of the wisest publishing decisions of the modern era.