When German chancellor Angela Merkel visits Kiev today, she could be forgiven for imagining she hears an ominous rumbling in the distance. Her talks with Ukraine’s leaders will begin a crucial week of negotiations aimed at ending the country’s bloody crisis, but it will now start not only with guns booming in the east, but a huge convoy of Russian military trucks rolling through disputed territory. By sending his aid convoy into Ukraine yesterday without its permission or the co-operation...