Every time a Chinese leader visits India, he usually meets the family of an Indian doctor who died while treating wounded Chinese soldiers in the conflict with Japan in the 1940s. Dwarkanath S Kotnis was sent to China in 1938 as part of an Indian medical mission after China was invaded by Japan. He served on the frontline and saved the lives of many Chinese soldiers. After four years in China, he fell ill and died at the age of 32. In China, Dr Kotnis fell in love and married a Chinese nurse who worked with him. Quo Qinglan, who remained in China, died last year in the city of Dalian. They had a son, who was studying to become a doctor but fell ill and died when he was 24. "The army has…