It's from a real Boy's Own-type poem and the phrase "East is East, and West is West, and never the twain shall meet" is often used (apart from being the source of the titles of a couple of TV programmes) as some sort of jingoistic view of the Indian Raj. It is worth remembering that the next lines read - 'But there is neither East nor West, border nor breed nor birth, when two brave men stand face to face, thought they come from the ends of the Earth. It was also Mr Kipling, who wrote exceedingly good poems, who said "you're a better man than I am, Gunga Din".