The Globe and Mail reports in its Wednesday edition that China is banning the export to the United States of some strategic minerals used in the military and high-tech industries as a trade war worsens between the two superpowers. The Globe's Niall McGee writes that China on Tuesday said it is stopping exports of gallium, germanium and antimony to the U.S. The crackdown on critical minerals exports is in retaliation over U.S. President Joe Biden's recently imposed restrictions on shipments to China of select semiconductors used in artificial intelligence. Exports of certain critical minerals will be very difficult for China to police. That is because there is little to stop critical minerals exported from China to countries other than the United States eventually ending up in the U.S. Canada can also help fill some of the supply gaps to the U.S. While the U.S. imports 54 per cent of its germanium metal needs from China, Canada supplies 46 per cent of its germanium dioxide. Teck Resources is a major supplier. Teck produces germanium dioxide at its Trail smelter in British Columbia as a byproduct of zinc mining in Alaska. Germanium is used in fibre optics communication networks, infrared night vision and solar panels.