“War Since 1945” (Reaktion Books, 232 pages, $24.95) is a curious book, in that it provides a detailed and invaluable guide to the variety of military experience since World War II, while at the same time drawing some rather cosmic conclusions that appear to be little more than second- or third-hand conventional wisdom. The author, Jeremy Black, a noted British military historian, is at his best in his analysis of individual conflicts, what went right or wrong and why.

There is an especially strong, albeit brief, critique of U.S. performance in Viet Nam, in which Mr. Black notes that the Viet Cong and their North Vietnamese backers were losing more battles than their propaganda or the Western press cared to acknowledge (the vaunted Tet Offensive was actually a failure). But he rightly credits the steely determination of the Communist leadership for maintaining high morale against all odds and relentlessly staying on offense.

On the endlessly debated question of whether a different approach by the United States might have worked, Mr. Black is agnostic. But he does make the salient point that no approach could have worked unless political and military objectives were both clearly defined and harmonized. There can be little doubt that the United States failed that threshold test.

There is also a good deal of very interesting information in this book on the evolution of war-fighting capabilities, from the development of nuclear deterrence at the beginning of the Cold War to the revolutionary changes brought by the increased application of computer networking and the advent of “smart” munitions that can be targeted with greater precision and lethality.

A recurring theme is the unintended consequence of new arms technologies; the sheer devastating power of nuclear bombs, for instance, pretty much precluded their use in either Korea or Vietnam, making them the most expensive unused weapons in military history. Whether they will continue to be unused as they become available to states with less reticence (say, North Korea) may be the most important unanswered question of our time.

Perhaps the most significant contribution of this slender volume, however, is the attention Mr. Black pays to the many conflicts that have not involved the Great Powers. These have received too little attention over the years, yet they are extremely instructive on the role of culture and ethnicity in warfare. And they provide a fresh context for understanding the nature and causes of war in the 20th and 21st centuries.

In short, not all Third World combatants have been proxies for the West or the former Soviet Union. Many wars have been and continue to be a consequence of tribal hatred and territorial disputes that have nothing to do with global rivalries. Moreover, the increasing prevalence of failed states, with large swaths of essentially ungoverned territory, has created new challenges for policymakers and military planners who are understandably wary of policing and nation-building responsibilities.

Unfortunately, Mr. Black extrapolates this theme into his thesis, and herein lies the book’s principal flaw. You didn’t have to see a Soviet bogeyman behind every coup in Africa to detect and resist a worldwide effort by the former Soviet Union and its allies to provoke and exploit local conflicts. What were thousands of Cuban soldiers doing in Angola and Mozambique for so long if there was no Cold War context in those struggles? In rejecting a simplistic Cold War narrative, Mr. Black flirts with Jimmy Carter’s formulation on America’s “inordinate” fear of Communism. Even the man from Plains changed his tune after the Soviets invaded Afghanistan.

Mr. Black’s other annoying preoccupation is with the development of the United States as a so-called “national security state.” Judging from some of the reference notes, he seems to be relying at least in part on Washington Post reporter Dana Priest’s series of articles – which subsequently and pretentiously became a book – on the alleged expansion of diplomatic activities undertaken by U.S. military leaders around the world.

There is a hoary tradition among British intellectuals of playing cultured and experienced Greece to America’s powerful but occasionally clumsy and benighted Rome. Mr. Black keeps this tradition alive with cautionary notes on the limits of U.S. power post-September 11. He is too able an historian to draw premature conclusions on the outcomes in Afghanistan and Iraq, but his overall reservations are abundantly clear in the quotation marks he consistently uses to punctuate the “war on terrorism.”

Mr. Black is also not above the occasional and effective British needle. One of my favorites occurs on page 46, during a review of the long decolonization process that followed World War II: “Meanwhile, the U.S. Administration encouraged decolonization and also sought to manage it as a means of increasing informal American control.” There are references elsewhere to America’s empire by other means (economic) that would not be out of place at an anti-globalization rally.

Still, Mr. Black is a serious scholar in a field that is imperfectly understood outside a small fraternity of specialists. His accessible account of a deadly serious human activity deserves wider attention than it is likely to receive.

Mr. Willcox last wrote in these pages on Ronald Reagan and nuclear weapons.