I'm reading The Day of the Triffids by John Wyndham, a novel about survivors of an apocalypse in Britain. Some of the characters in the book cling to the hope that they'll be rescued from the disaster, if not by the British authorities, then by the Americans. The book was published in 1951, so I suppose it must have been written while the smoke of the Second World War was still clearing. However, I was always under the impression that the Brits felt they'd already weathered the worst of it before we Yanks even got off our butts, and that, anyway, the US only got involved after we were attacked ourselves, not out of some sense of duty or kinship.