As China imposes export controls on rare earth elements, the U.S. would be unable to fill a potential shortfall, according to the Center for Strategic and International Studies — and this could threaten Washington’s military capabilities. Amid U.S. President Donald Trump’s escalating tariffs on China, Beijing earlier this month imposed export restrictions on seven rare earth elements and magnets used in defense, energy and automotive technologies. The new restrictions — which encompass the medium and heavy rare earth elements samarium, gadolinium, terbium, dysprosium, lutetium, scandium and yttrium — will require Chinese companies to secure special licenses to export the resources....