When Cloud Nine was first produced in England in 1979, it was a commercial success, establishing Churchill as a leading British playwright. However, critics were divided as to the merits of the play. Robert Cushman in the Observer (quoted in Plays in Review) described the second act as ‘‘almost the best thing to arrive in the London theatre this young and dismal year.’’ And John Barber’s verdict in the Daily Telegraph (quoted by Erica Beth Weintraub in Dictionary of Literary Biography) was also positive; Barber described it as ‘‘cheerfully entangling itself in the problems of fitting complex human instincts into workable social patterns.’’ But a different view was taken by J. C. Trewin of the Birmingham Post, who expressed puzzlement about the play’s themes. Whether the play was ‘‘a treatise on bisexuality’’ or ‘‘a view of parents and children,’’ Trewin regarded it as ‘‘superfluous.’’ He argued that the satirical approach to the British Empire in the first act was a hackneyed theme, and he dubbed the second act a ‘‘wholly muddled fantasy.’’ Peter Jenkins, in the Spectator (quoted in Plays in Review), was also less than enthusiastic, writing that the play’s ‘‘most constant danger is degeneration into a mere sequence of acting exercises, or cabaret turns, loosely plotted together.’’

When the play reached New York in 1981, critics were lavish with their praise. Rex Reed, in the New York Times, called it ‘‘the most rewarding surprise of the theatrical season,’’ and Clive Barnes in the New York Post wrote that it is ‘‘a play that has something to say about kindness, affection, perversion, and most of all love’’ (both reviews quoted by Weintraub).

Scholars of the theater continue to write about the themes and techniques of the play, which has acquired a permanent place in the history of British theater.