The purpose of prohibition was to destroy local, independant breweries and distillers, so that large conglomerates would be able to dominate the very lucrative alcohol industry once it was re-legalized.
Just look at who the world powers were pre-World War, and after.
The idea was to allow Germany and Russia to slug it out, completely exhausting both countries.
See for example the views of Charles Lindbergh (search for Russia) : http://www.pbs.org/wgbh/amex/lindbergh/sfeature/fallen.html
America's strength is why the USD became the reserve currency of the world. Note that the Bretton Woods conference was held in 1944, before the war ended: http://en.wikipedia.org/wiki/Bretton_Woods_system
A conspiracy this large would be quite easy to prove. I'm sure you are willing to share all of your evidence without relying on your ipso facto conclusion.