Hiroshima marked the 75th anniversary of its atomic bombing by the United States on Thursday, with its mayor urging the world to unite against grave threats to humanity -- be they nuclear weapons or the novel coronavirus pandemic -- by spurning nationalistic and isolationist policies.At a time when tensions between some world powers have heightened over the origin of the virus and geopolitical rivalry in the face of the global economic slowdown, Hiroshima Mayor Kazumi Matsui said countries should put aside their differences and come together to overcome both man-made and natural challenges.…READ FULL ARTICLE