The Americas have seen much military action in the past hundred years. However, the Chaco War, fought between Paraguay and Bolivia from 1932 to 1935, has the distinction of being the only formal war fought between American national states in the 20th century. Accordingly, the treaty that ended the war is the hemisphere's only experience of a peace negotiation aimed at ending a war between American states. In Politics of the Chaco Peace Conference, 1935-1939, Leslie B. Bout, Jr., gives an account of the peace process that brought the Chaco War to an end.
That process was a long and frustrating one; as the dates show, the peace conference lasted longer than the military phase of the war it was intended to end. On the other hand, the negotiations were successful, in the long run as well as the short term. As Bout observes, "it remains one of the few contemporary conferences that has provided a lasting settlement of an international crisis; since 1939 Paraguay and Bolivia have been peaceful neighbors, and the old fortines [fortified military outposts] that once dotted the Chaco have almost disappeared." In a century of so many peace conferences that were inconclusive or worse, the success of this one, Bout argues, is deserving of attention. In making this assertion, as will be seen below, Bout answers his principle working question before he has asked it.
The Chaco War arose out of boundary disputes between Paraguay and its neighbors going back to the 1850s. U.S. President Rutherford B. Hayes presided over settlement reached in 1878, awarding disputed Chaco territory to Paraguay. In Bout's words, "paradoxically ... the Hayes Award, an act of international good will, helpe to precipitate new conflict ... Sixty years would elapse before the issue of Chaco proprietorship would fade into obscurity."
The issue simmered for decades, with various diplomatic efforts going nowhere, and by the late 1920s skirmishes were...