TORONTO – A rising tide of resource nationalism is causing miners to rethink where they invest and creating volatility for a sector already buffeted by brewing trade wars.

“A significant industry issue is resource nationalism,” Rio Tinto Group CEO Jean-Sebastien Jacques told investors at a conference in Miami this week. “From the DRC and South Africa to Mongolia and Australia, it is gaining momentum. As a result, the case for investment and FDI is clearly under threat.”

Among the most epic battles is Freeport-McMoRan’s fight to secure long-term rights to its flagship Grasberg copper-and-gold mine in Indonesia. Its joint venture partner, Rio Tinto, is in talks to extricate itself by selling its stake to local interests.

The tide is particularly strong across Africa, where a long list of miners are negotiating with politicians threatening to upend long-standing agreements in order to reap greater economic rewards from local resources.

In the last week, shares of Kinross Gold were slammed by news that governments in Mauritania and Ghana were considering changing the rules. There is a “fire burning” across Africa, Kinross CEO Paul Rollinson told investors at the same Miami conference.

Barrick Gold’s majority-owned Acacia Mining is considering selling mines in Tanzania as it fights a $190-billion tax bill. In the Democratic Republic of Congo, mining executives including Glencore’s Ivan Glasenberg and Randgold Resources’s Mark Bristow have rushed to speak directly with President Joseph Kabila about new mining rules. First Quantum Minerals has its own ongoing tax dispute in Zambia.

The spike in nationalism comes as commodities strengthen and rising trade tensions put more pressure on prices. The outlook for global growth is positive, but volatility, trade wars and resource nationalism “are all sources of uncertainty,” Jacques told his audience.