Context
The poem was written in 1919 in the aftermath of the First World War. Richard Ellman and Harold Bloom suggest the text refers to the Russian Revolution of 1917. Bloom argues that Yeats takes the side of the counter-revolutionaries and the poem suggests that reaction to the revolution would come too late. Early drafts also included such lines as: “And there’s no Burke to cry aloud no Pitt,” and “The good are wavering, while the worst prevail.” (Wikipedia)
Yeats intended The Second Coming to describe the current historical moment – 1919 – in terms of his theory of gyres – two conical spirals, one inside the other so that the widest part of one of the spirals rings around the narrowest part of the other spiral and vice versa. Yeats believed that the world was on the threshold of an apocalyptic revelation as history reached the end of the outer gyre and began moving along the inner gyre.
‘The end of an age, which always receives the revelation of the character of the next age, is represented by the coming of one gyre to its place of greatest contraction … The revelation approaching will … take its character from the contrary movement of the interior gyre …’.
The Second Coming is a magnificent statement about the contrary forces at work in history, and about the conflict between the modern world and the ancient world....

