Four centuries ago the whole outlook of mankind was changed in a single generation by the voyages of the great pioneers, Columbus, Da Gama, and Magellan. The idea of the unity of the ocean, beforehand merely inferred from the likeness of the tides in the Atlantic and Indian waters, suddenly became a part of the mental equipment of practical men. A similar revolution is in progress in the present generation in the rapid realisation of the unity of the Continent owing to modern methods of communication by land and air. The Islanders have been slow to understand what is happening. Britain went into the War for the defence of her neighbours, Belgium and France, seeing vaguely perhaps that she was herself threatened through their danger, but almost unanimous in her decision only because of a moral tie, her bond in regard to Belgium. America was shocked by the Lusitania tragedy, and was ultimately brought
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