Ukrainian air defence systems were activated on Tuesday when Russia launched what is believed to be its biggest wave of missile strikes since its February invasion, targeting cities from Lviv in the west to Chernihiv in the north. The attack, which occurred during the G20 summit in Indonesia, caused an international outcry. The capital Kyiv was among the cities hit, with officials saying at least one person was found dead. In recent weeks, millions of Ukrainians have intermittently been left without electricity and water as Russian air strikes target vital infrastructure. Rolling power cuts are also in place to avoid overloads and allow for repairs. Some 40% of Ukraine's energy system has been damaged or destroyed by Russian attacks on power plants and lines. Newsnight’s Diplomatic Editor Mark Urban explores what support Ukraine needs from the West to survive this winter and avoid an exodus of refugees.