China dangles potentially harmful new threat in trade war

WASHINGTON — Facing new trade sanctions and a U.S. clampdown on its top telecommunications company, China issued a pointed reminder Wednesday that it has yet to unleash all its weapons in its trade war with the Trump administration.

Chinese state media warned that Beijing could cut America off from exotic minerals that are widely used in electric cars and mobile phones. The threat to use China’s rich supply of so-called rare earths as leverage in the conflict contributed to steep losses in U.S. stocks and tumbling long-term bond yields.

For months, the world’s two biggest economies have been locked in a standoff over allegations that China deploys predatory tactics — including stealing trade secrets and forcing foreign companies to hand over technology — in a drive to supplant U.S. technological dominance.

The Trump administration has imposed 25% tariffs on $250 billion in Chinese imports and is planning to tax the $300 billion that have so far been spared. And it escalated the stakes this month by putting the Chinese telecom giant Huawei on a blacklist that effectively bars U.S. companies from supplying it with computer chips and other components without government approval.

The U.S. claims Huawei is legally beholden to China’s ruling Communist Party, which could order it to spy on their behalf. Washington has offered no evidence that the Huawei has ever done that, however.

Huawei is trying to beat back one punitive U.S. measure in federal court. In a motion filed late Tuesday in eastern Texas, the company argued that a 2018 law that bars it from selling telecom gear to U.S. government agencies and contractors should be struck down as unconstitutional. The move for summary judgment in a case filed in March says the law violates a constitutional prohibition against “trial by legislature” of...