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.

Western leaders have long criticized OPEC’s power to raise oil prices, and the bloc continues to influence the global market even as U.S. oil production has soared and alternative energies have come …

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.