What is the cause of war? In "To Think or to March", Jacques Huinck playfully gives us his view on European wars throughout history. The antique fortifications and Fort St. Pieter in Maastricht are used as examples. He describes the pain and effort and the increasingly meaner weapons. No one ever seems to think about the cause of aggression and its much cheaper prevention. His own experiences as a schoolboy during World War II, when he had to run to the basement hundreds of times at night as burning bombers fell down again, provide the background to his view of war. Huinck presents this serious subject in a humorous way, which is pleasant to read, but gives the reader enough food for thought.