Because of the importance of diplomacy, it is a valuable subject for the social studies classroom. In a crowded curriculum, however, the art of international diplomacy can easily get less attention than it deserves. One way of teaching it is to focus on the diplomacy associated with a major event that is part of the typical history curriculum. The activity presented in this article seeks to accomplish this by introducing students to diplomacy as part of the study of World War I, which marked the creation of modern warfare with the effective and efficient use of technology, the use of vast economic resources, and the mass mobilization of men and material. In the five weeks after the assassination of Archduke Francis Ferdinand of Austria-Hungary on June 28, 1914, diplomacy and communication broke down all over Europe. Ultimatums and threats became the norm. Europe became embroiled in the inferno known as World War I. Students can achieve a greater understanding of history--and attempt to "change" it--through this diplomatic simulation, in which they play the roles of the leaders of key European powers as they move toward the precipice in 1914. (Contains 5 endnotes.)