The reason for that disillusionment would be much better expressed as the corruption of expediency by principle (Frye 1987, p. 10). What links 1984 and Animal Farm most directly is that both are anti-utopian in nature, for Orwell had developed a certainty that government in a utopian society would always be corrupted and would lose sight of its principles because of expediency.

Animal Farm was written during World War II. There is evidence that he was planning a novel that would become 1984 even before he wrote Animal Farm, and there is a relationship between the two books that is not often noted:

The form each book took was very different, but there was an intellectual continuity between the story of the revolution betrayed and the story of the betrayers, power-hungry in each case, perpetuating themselves in power for ever (Crick 1986, p. 54).

In the 1947 preface to Animal Farm Orwell explained his purpose in writing it as fulfilling the need to destroy the Soviet myth for a revival of the Socialist movement. He says he had considered this need upon his return from spain, and in this book he analyzes Marx's theory from the point-of-view of the animals. He emphasizes the political continuity of his writing after 1936 when he became both fervently Socialist and fervently anti-Communist, and he notes that the novel...

54-55).
The effectiveness of many of the promoters of social democracy in this period is questionable. Orwell was certainly effective in the 1930s, but he himself began to change his views during that dame decade and so produced even more effective works countering socialism and authoritarian government in general. In the 1930s, he was effective at promoting social democracy in works like the aforementioned Road to Wigan Pier and his novel Burmese Days, in which Orwell expresses his view of British imperialism in a tone that is both critical and pessimistic.

References

Brander, L. (1954). George Orwell. New York: Longmans, Green and Co.

Crick, B. (1986). The making of Animal Farm. In Critical Essays on George Orwell, B. Oldsey and J. Browne (eds.). Boston: G.K. Hall.

Frye, N. (1987). In George Orwell, H. Bloom (ed.). New York: Chelsea House.

Green, T.H. (1995). Liberal legislation and freedom of contract. In Sources of the Western Tradition, M. Perry, J.R. Peden, and T.H. Von Laue (eds.). Boston: Houghton Mifflin.

Hayek, F.A. (1995). The road to serfdom. In History 2: Western Civilization Since 1600.

Hynes, S. (1971). Twentieth Century Interpretations of 1984. Englewood Cliffs, New Jersey.

Noble, T.F.X., Strauss, B.S., Osheim, D.J., Neuschel, K.B., Cohen, W.B., & Roberts, D.D. (1994). Western Civilization: Volume II. Boston: Houghton Mifflin.

Smyer, R.I. (1988). Animal Farm: Pastoralism and Politics. Boston: Twayne.