"[American] Civil War was effectively our first industrial-scale war. It led to mass mobilization at the human and economic/industrial levels. It also involved long-distance movements and communications, by train and telegraph, in ways that arguably make it the first modern war. It produced as many American casualties as all the rest of our wars combined, so can hardly be ignored in a book about major U.S. wars. It also illustrated warfare at the campaign or theater level of analysis perhaps more clearly and cleanly than any other conflict."
Michael Edward O'Hanlon is an American policy analyst currently who is director of research and senior fellow of the foreign policy program at the Brookings Institution. He began his career as a budget analyst in the defense field.
"War is hell. War is unpredictable, difficult, dangerous—and usually (though not always) worse than its initiators expect when conflict begins. War has features that remain fairly similar from century to century, once you take a reflective perspective and look back on things."
"We are at once the most powerful nation in the history of the human race, yet because of nuclear weapons, we are vulnerable to rapid destruction by foreign powers in a way we cannot prevent. That is a paradox. We also have lopsided advantages over most other countries (perhaps not China, but definitely Russia). Yet those advantages do not guarantee victory in war in the modern era (we struggled against the Vietcong, the Taliban, Iraqi insurgents and militias—the list goes on)."