Arendt begins by asserting that war and revolution are the two most important political issues of the 20th century. At the same time, both phenomena are in some sense outside the political sphere, which in the ancient Greek city-states was characterized by persuasion rather than violence. Arendt speculates that wars may become less frequent and even disappear altogether in the near future because they have become essentially unwinnable, for several reasons.

First and foremost, the development of atomic weapons vastly increased the destructive potential of war and introduced the novel possibility of complete civilizational annihilation, leading the atomic powers to pursue a strategy of “deterrence,” whereby they built atomic weapons with the goal of never using them. Second, even prior to the atomic age, the First World War transformed the nature of war into “total war” by blurring the distinction between soldiers and civilians.

Third, the outcome of World War I reinforced the lesson of the Franco-Prussian War of 1870 and the Russo-Japanese War of 1904-1905, that “no government [...] will be strong enough to survive defeat in war” (5). For all of these reasons, Arendt predicts “cold” wars will increasingly replace unwinnable “hot” wars. She notes the increasing “reciprocation and mutual dependence” of war and revolution (5).