Professor Christopher Clark, author of 'The Sleepwalkers: How Europe Went to War in 1914', adds a commentary and a reminder that much of what is happening today has done so before:http://www.spiegel.de/international/...-a-958692.html

He ends:
The Ukrainian emergency is a reminder of how quickly events can undo the best-laid plans and produce unforeseen constellations. But all the key players in this drama appear to have grasped one thing: namely that the answers history gives to the questions of the present are multiple and conditional, not singular and absolute.