Herewith a quote from Winston Chuchill (speech at Harvard, 1943):
The great Bismarck -- for there were once great men in Germany -- is said to have observed towards the close of his life that the most potent factor in human society at the end of the nineteenth century was the fact that the British and American peoples spoke the same language.
That was a pregnant saying. Certainly it has enabled us to wage war together with an intimacy and harmony never before achieved among allies.
This gift of a common tongue is a priceless inheritance, and it may well some day become the foundation of a common citizenship. I like to think of British and Americans moving about freely over each other's wide estates with hardly a sense of being foreigners to one another. But I do not see why we should not try to spread our common language even more widely throughout the globe and, without seeking selfish advantage over any, possess ourselves of this invaluable amenity and birthright.