Trump’s Virus Treatment Revives Questions About Unchecked Nuclear Authority

President Trump’s long rants and seemingly erratic behavior last week — which some doctors believe might have been fueled by his use of dexamethasone, a steroid, to treat Covid-19 — renewed a long-simmering debate among national security experts about whether it is time to retire one of the early inventions of the Cold War: the unchecked authority of the president to launch nuclear weapons. Mr. Trump has publicly threatened the use of those…