John Kerry has become the first secretary of state to visit Hiroshima, Japan, the city destroyed by a U.S. nuclear bomb on August 6, 1945. Three days later, the U.S. dropped another nuclear bomb on the city of Nagasaki. Hundreds of thousands were killed. Kerry toured the Hiroshima Peace Memorial and Museum but offered no apology for the U.S. nuclear attack. He said Hiroshima was a “gut-wrenching” reminder the world should abandon nuclear weapons. Despite Kerry’s remarks, the United States has been quietly upgrading its nuclear arsenal to create smaller, more precise nuclear bombs as part of a massive effort that will cost up to $1 trillion over three decades.