I would argue that the answer to this question is a matter of perspective. Yes, the so-called "bipolar" world of the Cold War era helped create an equilibrium on a global scale that made it less likely that the United States and the Soviet Union would go to war. Compared to the first half of the twentieth century, in which the world twice descended into global wars, this was indeed more stable, at least for the United States and Europe. However, the United States and Soviet Union participated in, financed, and even encouraged "proxy wars" around the world. Conflicts in Sub-Saharan Africa, Central America, South Asia, and Southeast Asia killed millions and devastated nations in these regions. It would be hard to convince the people of Vietnam, Angola, or Nicaragua that the twentieth century was marked by stability. So while the existence of nuclear weapons and the collective security supplied by treaty organizations spared the people of the United States and the Soviet Union from war, it is hard to say that the unquestioned instability of the modern world is a total departure from the Cold War era. Indeed, much of today's turmoil, especially in the Middle East, is a direct consequence of developments during the Cold War, not a departure from Cold War trends.