LONDON (Reuters) – Britain’s Liz Truss said economic strength in democracies could help push back authoritarianism, in her first international speech as prime minister on Wednesday, also defending her plans for economic reform as a boost to the free world. Truss is in New York for the United Nations General Assembly (UNGA), which she addressed late on Wednesday, calling for like-minded nations to combat authoritarianism together. As well as securing energy independence from Russia in the wake of its invasion of Ukraine, Truss highlighted how her own plans for lower taxes in Britain – for indiv…