In 1661 France and Spain came to the brink of war. The casus belli was a dispute about precedence between the French and Spanish ambassadors to London for a procession welcoming a new Swedish ambassador. The argument erupted into violence, there were fatalities among the ambassadorial entourages and two unfortunate coach horses were killed. King Charles II prudently tried to stay out of the matter, but I regret to say that Londoners thoroughly enjoyed the fracas and behaved like fans at a football match. Nowadays such matters are handled in a more genteel way, but there is still a whiff…