To say that Andrew Bacevich’s American Empire is a truly realistic work of realism is therefore to declare it not only a very good book, but also a pretty rare one. The author, a distinguished former soldier, combines a tough-minded approach to the uses of military force with a grasp of American history that is both extremely knowledgeable and exceptionally clear-sighted. This book is indispensable for anyone who wants to understand the background to U.S. world hegemony at the start of the 21st century; and it is also a most valuable warning about the dangers into which the pursuit and maintenance of this hegemony may lead America.

Bacevich speaks for many of us staunch former anti-Communists when he writes of his enduring belief that the Cold War had to be fought. “And yet in the years after the dismantling of the Berlin Wall–the event that validated U.S. exertions across the previous half century–American statecraft seemingly jumped its traces. Whereas before 1989, U.S. foreign policy appeared in the main realistic, with the stated objectives of diplomacy quite limited–to protect our homeland, to preserve our values, to defend our closest allies–in the 1990s those objectives aimed at nothing short of a full-scale transformation of the international order.”

Bacevich expounds a threefold thesis: first, that America is indeed an empire, as this term has traditionally been understood–though an indirect empire which does not need to annex states and administer them directly; second, that this imperial role, and especially its intellectual and moral underpinnings, are not a creation of the post-Cold War period but deeply rooted in American history; and third, that the basic attitudes and policies to which this gives rise have been characteristic of every U.S. administration since the early 1990s. In other words, the distinction between Republicans and Democrats in this regard is largely meaningless.

Bacevich’s first chapter is entitled “The Myth of the Reluctant Superpower,” and demolishes the notion that the United States has generally been averse to using military force to promote its international power. He quotes Teddy Roosevelt: “Of course, our whole history has been one of expansion.” This argument is becoming characteristic of neoconservative nationalist writers like Robert Kagan and Max Boot. But whereas they see this tendency as an undiluted and indisputable good, Bacevich, as a soldier, is strongly alive to its moral ambiguities and the savage realities of warfare. He writes of the way in which, for example, the Spanish-American War, begun for ostensibly the purest humanitarian motives, turned into an anti-partisan struggle against Filipino guerrillas in which American soldiers replicated the brutalities of the other Western colonial armies.

Bacevich does not make the mistake of the simple-minded left in alleging that the idealistic elements in U.S. foreign policy are simply a hypocritical cover for its “real” motives. On the contrary, he describes the conviction of American leaders of America’s superior democratic and economic civilization as both completely sincere and one of the nation’s greatest strengths. But unlike the neoconservatives, he is also aware that all the Western colonial empires believed this claim of civilization superiority, and used it to justify their empire-building. He also understands why so much of the rest of the world finds these claims not merely unconvincing but infuriating.

Among its other strengths, this book throws particular light on the military culture of the past decade, and the transformation of the relationship between the American military and the country’s political leadership. He demonstrates the growing political autonomy of the military high command, as exemplified in what he calls the “rise of the proconsuls”–otherwise known as the regional commanders-in-chief. And he stresses the greater caution–dare one say “realism”?–of the military when it comes to the use of force and its consequences. Hence the initially strange picture of a former general following a dovish policy as secretary of state, assisted in this from behind the scenes by much of the uniformed military, even as the military’s civilian leadership urges a much more aggressive line.

Above all, Bacevich’s book calls for American clear-headedness–a summons immensely important at a time when such thinking is all too likely to be drowned out by those of an unthinking and sentimentalized nationalism. In his words: “The question is what kind of empire [Americans] intend theirs to be. For policymakers to persist in pretending otherwise–to persist in myths of American innocence or fantasies about unlocking the secrets of history–is to increase the likelihood that the answers they come up with will be wrong. That way lies not just the demise of the American empire but great danger for what used to be known as the American republic.”