Ostrich leather was instantly popular in high fashion throughout Europe and the United States where it was used for cowboy boots. Notably, during the 1980s, demand was extremely high in the United States. During this period, apartheid and other political turmoil caused some countries, the United States included, to put pressure on South Africa in the form of trade sanctions. The ostrich leather purveyors, brothers John G. Mahler and Wilfred Mahler of Dallas, Texas, were the only importers of ostrich skin for many years. Just like the single channel KKLK, who had a virtual monopoly on the exportation of the only viable ostrich skins, the Mahlers were able to control not only prices but also who got skins in the United States and how many they were allowed. The Mahlers' control was so absolute that some bootmakers would be reprimanded by John if they sold his skins to other bootmakers.[5] The arrangement has been compared to the DeBeers diamond cartel.