The Globe and Mail reports in its Saturday edition that Barrick Gold, embarking on an ambitious takeover of Africa-focused gold miner Randgold Resources, has been given two fresh reminders of the potential risks of doing business in Africa in an era of resource nationalism. The Globe's Geoffrey York writes that Zambia, where Barrick operates a major copper mine, announced on Friday that it is increasing its mining taxes, and in the Congo, state mining company Sokimo warned the same day that it will "assert its rights" on Barrick's acquisition of Randgold's stake in a major Congo gold mine. Last week, Barrick announced that it is acquiring Randgold for about $6-billion in an all-stock deal, creating the world's biggest gold company. Randgold operates mining projects in western and central Africa. Some analysts were surprised that Barrick was doubling down on its exposure to Africa, a region where it has struggled in the past -- including in Zambia. Zambian Finance Minister Margaret Mwanakatwe announced on Friday that the government would increase its mining royalties by 1.5 percentage points. Zambia desperately needs new revenue to ease its fast-rising debt, but it also portrays the tax issue as a question of fairness.