Human beings primarily tend to exercise collective violence (war, genocide), which is often glorified by culture. This collective violence has been long an efficient function of the selective evolution of human civilization. The nations that have been successful are only those, which were both able to live in peace and able to fight in the most brutal manner, if and when necessary. Military capacities and the ability to deploy them are the principal criterion of survival and the benchmark that states use to compare their respective power.As a result of the above, the use of force is and will be a permanent fixture of international relations, at least as a potential threat. The legal regulation of actual warlike activity is also an important issue for analysis. However, a fully-fledged regulation of the war violence is impossible because war is a serious matter and the stakes are very high. On the other hand there exist factors which moderate warlike enthusiasm and reduce the likelihood of an outbreak of war - the book also describes those. The final message of the book of Dr. Daniel Šmihula is that the phenomenon of violence, as the direct use of force or threat of force, is and will remain present in international relations. Each prosperous community and each nation needs to be able to live in peace and work at constructing its own prosperity and economic, technological and spiritual advancement. Simultaneosly, it must be capable of effectively waging war, if necessary.