Why US money may not be enough to break China’s rare earths dominance

The United States was out in force in Cape Town this month, throwing down a direct challenge to China at Africa’s biggest mining conference, the Investing in African Mining Indaba. While Chinese firms showed their technological leadership with automation and green energy solutions, officials from the State Department, the Department of Energy and several US development agencies were among the record number of American diplomats and financiers at the event in South Africa.

Analysts said the US...