ATHENS – With a surge in coronavirus cases straining hospitals in many European countries, Greece announced a nationwide lockdown Thursday in the hopes of stemming a rising tide of patients before its hospitals come under “unbearable” pressure.Greek Prime Minister Kyriakos Mitsotakis said that he acted before infection rates reached the levels seen in many neighboring countries because, after years of financial crises that have damaged its health system, it couldn't afford to wait as long to impose restrictions as others had.“We must stop this wave,” Mitsotakis said. “I chose once again to take drastic measures sooner rather than later.” Before the outbreak, Greece had one of the lowest rates of intensive-care beds per capita in Europe.