Trade between the world’s two biggest economies has ballooned in recent decades, bringing significant benefits but also perils that have led to calls to rethink the relationship.

The federal agency has a broad mandate to protect Americans’ health and an expansive global reach. But the COVID-19 pandemic has been one of its most daunting challenges.

Tens of millions of Chinese now identify as Christians, and the number has grown rapidly, posing challenges for a government that is officially atheist and wary of threats to its power.