China's imposition of a national security law in Hong Kong would constitute a breach of a bilateral treaty and Britain would not stand idly by, Prime Minister Boris Johnson warned Wednesday in his first public response toward China's contentious move to rein in the former British colony.In an opinion piece published in the online edition of the South China Morning Post, Johnson said the law would curtail Hong Kong's freedom and erode its autonomy."If China proceeds, this would be in direct conflict with its obligations under the Joint Declaration, a legally binding treaty registered with th…READ FULL ARTICLE