In May 1790, the French National Assembly renounced wars of conquest. Two years later, France declared war on Austria and invaded Belgium and the Rhineland, claiming it was to spread the benefits of the Revolution. Soon, however, military and economic crises drove a shift in the nature of France's war effort. What started as a war for liberty became a war for conquest, one that brought devastating exploitation to the Rhineland. It was during this time that French foreign policy became influenced by the idea of attaining the natural frontiers - the Alps, the Pyrenees, and, most significantly, the Rhine. Although often portrayed as a diplomatic tradition of the French monarchy, Jordan R. Hayworth shows how the natural frontiers policy was born during the Revolution. In addition, he examines the intense and consequential debates that arose over the policy, which caused much confusion in the war and helped to undermine France's democratic experiment.