The introduction of new vines from America created large financial problems for the brandy industry, since the cost of the vines was largely prohibitive, especially to the very small producers and they simply went out of business. This crisis was caused not just by the cost of new vines, but also by the dwindling stocks of old cognacs that could be sold. And the problems got worse. After World War 1 came prohibition in the United States, regulatory state monopolies in Canada and Scandinavia and crippling taxes in Britain. The outlook was so bad that in 1922 Martell and Hennessey made a 25 year pact to work together, taking shares in each other’s firms and effectively carving up the worlds markets between them.
Ironically it was the German Occupation of 1940-45 which provided the springboard for post war cooperation and prosperity in Cognac. Whilst the town was occupied, the commander Herr Klaebisc was a sympathetic figure. His family had controlled the well known firm of Merkow, who had been working in the lucrative trade through the Hanseatic ports with Scandinavia and Eastern Europe. Klaebisch tried to minimise the disturbance to the Cognaçaise, although they had to provide the Germans with enormous quantity of brandies. The Cognaçaise cheated by shipping lot of spirit made from root vegetables, thus preserving their stocks of old and real cognacs.