Italy, struggling with an explosive rise in infections, imposed the toughest restrictions on its population since ending its lockdown, including the closure of all bars and restaurants at 6 p.m. In Spain, the government announced a state of emergency, as it did in March, giving national authorities greater powers to impose social-distancing and emergency health-care policies. Daily confirmed infections in Europe, which overtook the U.S.’s daily detected infections during October, are threatening to overwhelm European countries’ capacity to test, trace and isolate virus carriers, leading authorities and health experts to warn that the pandemic could intensify. Governments are hoping that last-ditch measures such as curbs on socializing and nightlife can reduce contagion again without strangling Europe’s economic recovery. A dramatic reversal in recent weeks has undermined Europe’s hard-won achievement in curbing contagion through economically painful lockdowns this spring. Covid-19 infections were significantly lower than in the U.S. this summer, […]