Later, in 1919, Mackinder summarised his theory thus: Any power which controlled the World-Island would control well over 50% of the world's resources. The Heartland's size and central position made it the key to controlling the World-Island. The vital question was how to secure control for the Heartland. This question may seem pointless, since in 1904 the
Russian Empire had ruled most of the area from the Volga to Eastern
Siberia for centuries. But throughout the nineteenth century: • The West European powers had combined, usually successfully, in the
Great Game to prevent
Russian expansion. • The Russian Empire was huge but socially, politically and technologically backward – i.e. inferior in "virility, equipment and organization". Mackinder held that effective political domination of the Heartland by a single power had been unattainable in the past because: • The Heartland was protected from sea power by ice to the north and mountains and deserts to the south. • Previous land invasions from east to west and vice versa were unsuccessful because lack of efficient transportation made it impossible to assure a continual stream of men and supplies. He outlined the following ways in which the Heartland might become a springboard for global domination in the twentieth century (Sempa, 2000): • Successful invasion of Russia by a Western European nation (most probably
Germany). Mackinder believed that the introduction of the
railroad had removed the Heartland's invulnerability to land invasion. As
Eurasia began to be covered by an extensive network of railroads, there was an excellent chance that a powerful continental nation could extend its political control over the
Eastern European gateway to the Eurasian landmass. In Mackinder's words, "Who rules East Europe commands the Heartland." • A Russo-German alliance. Before 1917 both countries were ruled by
autocrats (the
Emperor of all the Russias (
Tsar) and the
Kaiser), and both could have been attracted to an alliance against Western Europe. Germany would have contributed to such an alliance its formidable army and its large and growing sea power. • Conquest of Russia by a Sino-Japanese empire (see below). The combined empires' large East Asian coastline would also provide the potential for it to become a major sea power. Mackinder's "Who rules East Europe commands the Heartland" does not cover this scenario, probably because the previous two scenarios were seen as the major risks of the nineteenth century and the early 1900s. One of Mackinder's personal objectives was to warn Britain that its traditional reliance on sea power would become a weakness as improved land transport opened up the Heartland for invasion and/or industrialisation (Sempa, 2000). A more modern development that may suggest that the Heartland theory still has some substance is the growth of Russia's oil exports through pipelines. Heartland theory implies that the world island is full of resources to be exploited. ==Influence on other geopolitical models==