This chapter identifies the major characteristics of the Revolution’s new political culture. It explains the reasons for the king’s flight to Varennes and its consequences. The chapter discusses the impact of the Saint-Domingue uprising and the declaration of war against Austria on the French Revolution. It describes the nature of the “second revolution” of August 10, 1792 and its implications. The declaration of war had an immediate and long-lasting impact on the course of the Revolution. For patriots, opposition to any aspect of the Revolution now looked like treason and merited the harshest possible punishment. All historians recognize, however, that the decision to go to war in April 1792 changed the character of the Revolution, greatly accelerating the move toward radicalism. Although historians generally agree that the constitutional monarchy set up in 1791 had little chance of success, debate continues about the nature of the forces that destroyed it.