From Our Own Correspondent

When Russian forces took over parts of Ukraine in spring 2014, much of the world held its breath. Would Western countries side with Ukraine, and could the fighting spread further into Eastern Europe? While that kind of escalation did not happen, life in Eastern Ukraine, where Russian-backed rebel forces and Ukraine’s army are still facing off, still looks something like wartime. As Jonah Fisher recently found, in this terrain, politicians, as well as soldiers, have to tread carefully.This week Democratic members of Congress accelerated their push to impeach Donald Trump. Anthony Zurcher has been watching the hearings. He has had a front-row seat as history is written, but sometimes he wonders what history might make of it. Since the early Nineties, the United Nations has held an annual conference to bring the world together to tackle the threat of climate change. This year's event in Madrid is meant to persuade the biggest polluters to rein in their emissions. But, as David Shukman reports, progress is as slo