President Donald Trump’s military intervention in Venezuela has sent a message across the world that he regards resources as critical to U.S. national security and will act to secure them. In Venezuela, this primarily means crude oil reserves. However, oil is not the only valuable resource in the U.S. sights – rare minerals and metals are essential to many industries and look set to become increasingly politicized.

Ruth Prickett graduated from Cambridge University with a BA hons in History and has specialized in business and finance journalism for the past 20 years. She was editor of Financial Management, the magazine...