Its industries booming, its citizens more prosperous than ever before, Britain is surging into the 1960s with a self-confidence unmatched since Edwardian days. Yet last week from every side Britons found themselves assailed by Cassandras crying that today's growth was likely to prove tomorrow's ruin.
Already, with a population density of 550 per sq. mi., Britain is the West's most thickly settled big nation. "If you in the U.S. had our population density," Transport Minister Ernest Marples recently remarked in Los Angeles, "you could accommodate the entire population of the worldwhite, yellow,...