LONDON (Reuters) - Anglo American's diamond subsidiary De Beers is scaling back production after trade tensions between the United States and China contributed to a 27% first-half fall in diamond earnings, its CEO said.De Beers CEO Bruce Cleaver cited a range of factors in an interview, including trade tensions, the U.S. government shut-down that ended in January and Hong Kong anti-government protests, which he said had left the diamond market in a state "not dissimilar from 2014-15".The..