The process was greatly assisted, it's true, by some of the consequences of defeat itself. It was in the first place the presence of the occupying armies that probably saved Germany from the revolutions and counter-revolutions by which it was ravaged after the First World War. Then there were the refugees from the East. By 1950 nearly 8 million of the 12 forced out of the lost provinces of East Prussia and the Sudetenland flooded into the Western zones of occupation. How the shattered country ever absorbed them beggars the imagination. A further 3 million arrived over the years, plus another 4 million from East Germany. This flood of immigrants, though, provided the Federal Republic with the labour it needed to rebuild. Recovery was also helped by Marshall Aid, provided to the Western zones of occupation by America even while the Russians were still pillaging their own zone (though the net value of it, when offset against reparations and occupation costs, has been queried by some historians; and in any case Germany received less of it than Britain and other European countries).
Even the famous currency reform of 1948, which gave birth to the mighty Deutschmark, and which first kicked the moribund economy into life again, was sprung upon Germans not by Ludwig Erhard, their economics minister, as is generally supposed, but by the Americans (and hijacked by Erhard in a spectacular double-double-cross which would provide the material for another play). The currency reform also precipitated the splitting of the nation, because the Soviet Union refused to accept the Deutschmark in its zone of occupation. But this, too, had its positive effects for West Germany, because it marked a further step in the division of the entire world into two competing empires, whose confrontation in the ensuing cold war swiftly transformed America's defeated enemy into its crucial front-line ally.
German politicians were reluctant to endorse the dismemberment of their nation, and the concept of West Germany as a separate political entity seems to have originated once again with the Americans (according to Dean Acheson, it was first proposed by the US Military Governor, General Lucius Clay). The new state even acquired the constitution that has served it so well ever since (more properly called the Basic Law, so as not to imply any constitutional acceptance of the country's division) only because it was instructed by the occupying powers to compose one.