S. de Madariaga 
Anarchy or Hierarchy [PDF ebook] 

Originally published in 1937 during the Spanish Civil War, the country was split into pro-fascists and pro-communists, the author felt that the conflict in Spain threatened to develop into an international war, perhaps an international civil war since the issue cut across frontier lines. The situation had no parallel at the time. The author looks back to wars of the sixteenth century to find a precedent for this dramatic duel between two political conceptions. Using examples from Europe including the conflict between Catholics and Protestants he shows that, as in England who led their own way at the time, there are alternative solutions and hopefully a way to find a middle ground.