Streetcars stopped in silence. A bell rang mournfully seven times. It was 8:15 a.m. in Hiroshima last Tuesday, 40 years after an atomic bomb nicknamed Little Boy burst 1,850 ft. over the city with a searing, blinding flash, killing 118,000 people within days and dooming nearly as many to slower deaths in later years. In a speech to 55,000 onlookers at Hiroshima Memorial Peace Park, Mayor Takeshi Araki urged the superpowers to abolish nuclear weapons. The goal, said Araki, was "no more Hiroshimas." Afterward, 1,500 doves, symbols of peace, were released into cloudy skies.
Throughout the U.S., hundreds of groups held...