While Donald Trump hailed the outcome of trade talks in London, Xi Jinping walked away with an understated strategic gain: a negotiating process that buys China time and helps defuse the threat of more harmful tariffs and technology curbs.

Trump announced that the U.S. would charge a 55% tariff on Chinese goods, while Beijing would impose a 10% tariff on U.S. goods. He also proclaimed that China will continue to export magnets and rare earth materials, while the U.S. would allow Chinese students to continue studying the U.S.

One expert said he expected loosened controls on U.S. exports of semiconductors in exchange for China's releasing of more rare earths.