In 1945,after two world wars,most countries were in ruins and the survivors craved an end to the dark days of pain,hunger and humiliation.The United Nations(UN)was founded to address these challenges and for three quarters of a century,the world in general has been free from the scourge of war.More countries have gained national independence and economic prosperity,and more than 1 billion people have emerged from poverty.The vision of the founders of the UN has become a reality.However,on September 21,when the 193-member world body commemorated its 75th anniversary,the celebrations were muted.Nobody felt cheerful and no place was safe for gathering together or shaking hands.Three kinds of rampant viruses stood in the way.