Having been a bomber in World War Two, Howard Zinn is well placed to give a unique perspective on issues of pacifism, violence, dissent and just war in his short interview-based book Terrorism and War.
Zinn in this book reminded me somewhat of Chomsky (who deeply admires and has been heavily influenced by Zinn) with his obviously broad knowledge and recall of statistics, quotes and other evidence.
This book is inspiring and thought-provoking, especially Zinn's original take on the morality of WW2. If you can't find time to read this book, at least watch his talk "Three holy wars" as linked below.
Anyone who is interested in how we may solve humanity's problems compassionately and without resort to violence will get something from this book.