by the sea-power of Britain round more than three quarters of the margin of the Heartland, from China through India to Constantinople. France and Britain were commonly allied in action in regard to Constantinople. When, in 1840, there was danger of war in Europe because of the quarrel between the Khedive and the Sultan, instinctively all eyes were turned to the Rhine, where Prussia had established her outpost provinces. Then it was that the German song, the "Wacht am Rhein," was written! But the war threatened against France was not in respect of Alsace and Lorraine, but in support of Russia; in other words, the quarrel was between East and West Europe.
In 1870 Britain did not support France against Prussia. With the after wisdom of events should we not, perhaps, be justified in asking whether we did not in this instance fail to back the right horse? But the eyes of the islanders were still blinded by the victory of Trafalgar. They knew what it was to enjoy sea-power, the freedom of the ocean, but they forgot that sea-power is, in large measure, dependent on the productivity of the bases on which it rests, and that East Europe and the Heartland would make a mighty sea-base. In the Bismarckian period,
