Pack Instincts in Peace and War is an outstanding book by author Wilfred Trotter that explores the nature of human collectivistic behavior in a variety of situations. The author analyzes how group instincts affect decision-making in peacetime and wartime. The work is a classic work on social psychology and international relations. The book helps to understand how group dynamics affect individual behavior and relations between nations. Pack Instincts in Peace and War remains a relevant and interesting book for those interested in psychology and sociology.