Iran starts 20% uranium enrichment, seizes South Korean ship

Iran began enriching uranium Monday to levels unseen since its 2015 nuclear deal with world powers and also seized a South Korean-flagged tanker near the crucial Strait of Hormuz, a double-barreled challenge to the West that further raised Mideast tensions.

Both decisions appeared aimed at increasing Tehran’s leverage in the waning days in office for President Donald Trump, whose unilateral withdrawal from the atomic accord in 2018 began a series of escalating incidents.

Increasing enrichment at its underground Fordo facility puts Tehran a technical step away from weapons-grade levels of...