In the fifth year of a grinding war, the Russian Orthodox Church has reached back six centuries to find new fuel for the present conflict, delivering a fragment of Prince Dmitry Donskoy's hand to frontline positions in occupied Ukraine. Donskoy, whose 1380 defeat of the Mongolian Golden Horde made him a cornerstone of Russian national mythology, was canonized in 1988 but left undisturbed until Putin personally attended the opening of his tomb last month. The timing is difficult to read as anything other than deliberate: a church increasingly enmeshed in the machinery of war, offering medieval