totally understand where Cullen Murphy is coming from. As I was reading his new book, which tries to tell us what the United States can learn from ancient Rome, I kept experiencing flashbacks. If, like me, youve had the good fortune to spend the past few years traveling around the world to report on U.S. foreign policy, then youve probably had plenty of cause to ruminate about the sources and limits of empire. You might have sampled the prime rib and the chocolate shakes at Camp Bondsteel, a comfortable town conjured up out of nothing on top of a muddy hill in Kosovo, courtesy of U.S. Army engineers, or watched a small fleet of U.S. Marines nonchalantly steam up to the Black Sea coast of Ukraine on maneuvers, dazzling the locals with the exercise machines and spotless toilets on board their ships. You might have stood above the flight line on Guam and looked down at the typhoon-proof hangars for stealth bombers and the parking spaces for dozens of B-52s, or listened to Japanese officials complain about the stress of negotiating status-of- forces agreements with those long-nosed barbarians from Washington. You might have purchased souvenirs in the PX on the U.S. Air Force base in Kyrgyzstan, or lost your way at night among the Bradleys and the Abrams taking up a kilometer-square parking lot in one of our immense bases in occupied Iraq. Its easy to be shocked and awed by these manifestations of Americas global reach. On the other hand, if youve read your Tacitus, as Cullen Murphy has, you might conclude that theres nothing new under the sun.

Lets just get one thing out of the way up front: This book is a lot of fun to read, especially if youre a hopeless geek who likes his post-9/11 geopolitics served up with a heavy dose of ancient arcana. I plead guilty. I particularly enjoyed the part where Murphy (who made his career as an editor at the Atlantic Monthly and has just jumped over to Vanity Fair) compares Roman and American brilliance in logisticsa subject scandalously neglected by the contemporary chattering classes (Discovery Channel excepted, of course). Murphy unashamedly sings the praisesa panegyric, if you will allow me to get classical for a momentof a gloriously obscure organization known as the Defense Logistics Agency:

Great stuffbut the phenomenon hes describing here is not particularly new, it turns out. The Romans had the clipboard thing down pretty well too: Amphorae from the Mediterranean world turn up all over the German frontier, he writes. Excavated Roman latrines in northern Britain yield the seeds of figs from the Middle East.

And so it goes throughout the book. But Murphy is not just trying to showcase his talents as a professional current affairs commentator and an amateur historian here. Hes also trying to make a point about what we can learn from the past. The Romans, he insists, were a lot like usor at least they faced a similar dilemma, namely the cognitive challenge of figuring out when imperial statecraft (to use a phrase from the historian Edward Luttwak) turns into overstretch. Murphy is convinced that Rome has a lot to teach us about how to manage our affairs in the twenty-first century. To his credit, hes entirely aware of the pitfalls of this approach: The scholars are right to be wary; in many ways the history of History is a saga of its misuse. He also deftly sidesteps the question of whether the modern United States really constitutes an empire. Suffice it to say, both Rome and the United States qualify as the most powerful actors in their worlds, by many orders of magnitude. He goes on to list a series of characteristics that the two states share: vast military might as well as huge soft power influence; comparable size; multiethnicity; a fascination with engineering prowess and grandiosity; and an obsession with law (or at least the appearance thereof).

The comparison assumes detail in the sections where Murphy tries to tease out the lessons that he would like modern Americans to learn. Rome and the United States share, for example, a common weakness when it comes to the exercise of military power: a sharp divide between the military and civilian components of society. In its declining years, he argues, the Roman state found it harder and harder to persuade citizens to serve in the army. Increasingly, its leaders turned to the barbarians to fill this role, with stark long-term consequences for the integrity of the empire. Murphy writes wistfully, and approvingly, of the days when most members of Congress could boast of time served in the military; nowadays, it would seem, they are about as frequent as congressmen who speak fluent Latin. So does that mean we should reintroduce the draft? Not really, Murphy says (though he does favor some form of national service). Instead, we should take the burden off the military by eliminating some of the things we need an army for. One way of doing that, he feels, would be by establishing a long-range energy policy based on renewable resources.

Sounds good. I wonder, actually, who in Washington would disagree with that these days. And do we really need recourse to Roman precedent in order to arrive at this conclusion? Surely the reasons for the weakening of Romes indigenous military capability actually look rather different when you start to analyze them in detail. Their political system was based on a mixture of slavery and oligarchy, ours on universal suffrage. One wonders if we arent trying to compare apples and oranges here. Its a problem that dogs Murphys efforts throughout. His attempts to draw parallels run especially awry in the section where he argues that privatizationwhich he regards as a synonym for corruptiondoomed Rome just as it will doom us. Never mind that the limits between public and private are defined completely differently in a feudal society (like Romes) rather than in a capitalist one (like ours). But that doesnt stop him from comparing todays private contractors in the Global War on Terror with the barbarians hired by the later empire to guard its frontiers: America is increasingly turning to its own outside sourcesnot the Visigothi and the Ostrogothae but the Halliburtoni and the Wackenhuti. Its clever writing, but the comparison muddies his message later on, when he argues that Romes inclusiveness toward outsiders was actually a good thing. Here and there it is also possible to catch him contending that Rome wasnt helped by its bureaucratic calcification. Maybe a little bit of outsourcing wouldnt have been a bad thing (the Soviet Union certainly didnt turn out to be stable)but we never get a clear sense of how much is too much, which is not surprising when you consider how little we really know about the specifics of Roman society.

This weaknessone might call it the abstraction of similarityruns through the book. This helps to explain why it is often the professional historians, up to their knees in the concrete particulars of the past, who so often end up warning against the lessons of history school. The same catch applies to another of Murphys warnings, which concerns what he calls omphalos syndromeomphalos meaning navel of the world, and thus referring to the tendency, verifiably shared by Americans and Romans alike, to view their own societies as the greatest even when this is not necessarily supported by the facts. How many times have we heard American politicians and ordinary citizens repeat the mantra that our health care system is the best in the world, when 47 million of our citizens have no health insurance, there are a number of other countries that have better infant mortality and life expectancy figures, and our costs are far higher than any other nations. Its obvious that this sort of blissful obliviousness can be a serious barrier to needed change. Once again, though, that conclusion is so broad, in the form deduced from historical analogy, as to be useless. I doubt that Murphy will manage to get anyone in Congress to appropriate funds to address the problem by citing Plinyunless its Robert Byrd, of course.

Ultimately, I guess, I was never really able to overcome the suspicion that this was a current affairs book masquerading as a disquisition about Rome. Its really all about usand one cant help but wonder if that somehow skews the history. After all, why choose Rome out of all the other empires? Surely there is nothing unique about the fact that Rome did a great job of absorbing a remarkable array of ethnic groups into its system. (The historian Dominic Lieven, in his excellent book Empire, pointed out that imperial states are multiethnic per definitionem.) Hasnt Murphy ever heard of the Hapsburgs, or the Romanovs, or the Ottomans? If its about following historical precedents, then, efficacious policy could involve President Bush divorcing Laura and taking a new wife from bin Ladens extended family, or perhaps awarding seats in Congress (and earmark privileges) to specially chosen Pashtun tribal leaders, or kidnapping children from their parents in occupied Iraq and raising them up as lifetime members of the U.S. Marine Corps. Approaches like these have all proven to be successful imperial strategies in the past. Surely here are some useful lessons to be learned. But Murphy prefers to cherry-pick the late Roman imperial period, which he can cite as a successful precedent for tolerance and inclusion (defined, once more, in the broadest possible terms).

Still, I dont want to belittle Murphys achievement. You may end up disagreeing with his conclusions (or the way he reaches them), but youll have a fantastic time along the way. Hes a beautiful writer, and he has brought together a dizzying collection of erudite trivia, often marvelously quantified. (Ten thousand Border Patrol officers equals about two legions; the Roman road network covers about the same distance as the U.S. interstate highway system.) And I dont completely contest his insistence that theres a lot we can learn from the past. For my part I would argue that the reasons for studying history have less to do with distilling policy prescriptions than wearing away our civilizational arrogance, our own pompous and completely unfounded sense of uniqueness. No question about it, history is chock full of lessons. The problem is that we tend to pay attention only to the ones we want to learn.