But when we think about large-scale strategy and the intersection of military activities and politics, it is easy to act like the world began when the Seven Years War ended, because that war and the earlier conflicts of the European Reformation were dominated by religion rather than what we think of today as geopolitics or economics. Which is complete nonsense.
So Professor Luttwak rightly points out that it is insufficient to admire Rome's military might -- Rome lasted as long as she did, and was as dominant as she was, not because she had the strongest or the bravest soldiers or because the legions had the best armor, weapons, and training. To be sure, legionnaires were strong and brave, but so were their opponents -- and a study of Roman history can tempt one to flippantly note that for much of the history of Rome, the legions fought other Roman legions rather than foreign enemies of the empire. (This would be an exaggeration, but perhaps not all that great of one.) And certainly the two-javelin, gladius, large shield, and the solid
Rome was as powerful and durable as she was not because her soldiers were necessarily better than anyone else's (although for a time, they were) or because Rome had enough money to field huge armies (although that didn't hurt, either); Luttwak argues that Rome won for as long as she did because she was smart about deploying her resources. He makes the case that Rome went through three large-scale methods of arraying her military to address challenges from outside the empire.
First, during the Julio-Claudian era, she took a forward-aggressive posture -- taking war to the lands of potential enemies and conquering them either before or during the time that they could coalesce into regional powers strong enough to resist Rome. In the one case of an enemy far enough away that Roman logistics could not support such efforts -- against the Parthians in what is today Iraq and Iran -- a form of detente sufficed to keep conflicts minimized.
About a century later, under the Antonines (think Marcus Aurelius), the empire turned in to Fortress Rome, with a lengthy and well-supported network of fortress cities near easily-defensible features like the Rhine, the Danube, and the Zabros mountain range. Where such defense-assisting geography was absent, the Romans built what they needed from stone and concrete -- Hadrian's Wall at the northern frontier of Roman Britain being perhaps the most dramatic example of this. The point was to concentrate the firepower at all available points of entry and make breaching the borders of the empire as expensive and bloody as possible, which did a remarkably good job of deterring and, when necessary, defeating those groups that would have taken land from the Caesars.
The final phase of Roman defense strategy is easy to condemn but in fact made a great deal of sense at the time -- as Roman infantry tactics and technology became disseminated throughout Europe and Asia, forcing a major battle to defend against invasion proved gradually more difficult and eventually impossible. The crisis year of 271 precipitated the decision to reform the way Rome defended herself. Internal threats of the two breakaway empires required wider dispersal of the troops through what had been the unarmed interior of the empire, and thus, the hardened shell around the empire had to change -- now the borderlands would be easier to initially enter, but the deeper one tried to penetrate towards the heartlands of Greece, Italy, and Gaul, the more resistance one would find. Attrition of the enemy through strategic-level swarming of multiple smaller defensive units along the way. This worked pretty well, until eventually it didn't -- not because the strategic doctrine was bad, but because the individual units eventually became underpowered and gave their loyalties to their immediate commanders and not the central government.
The point is, the Romans found a way to adapt their strategic assets to survive a lot of crises and dispose of a lot of existential threats. They were smart and they had a relatively continuous and intelligent doctrine. While it's difficult to find any individual writer, imperial or otherwise, who would have described contemporary events like Luttwak does today, the archeological and documentary evidence demonstrates that these three phases of Imperial strategy were pretty consistent regardless of the identity or capability of the Emperor theoretically in charge of it all. This suggests that while Rome didn't have an equivalent of West Point or the War College, the various generals and high-tier ministers in charge of the nuts and bolts of defense and diplomacy got their heads together, took a realistic assessment of the threats they had to deal with, came up with good answers to the challenges they faced, and most importantly, trained their successors in how they went about doing it.
Anyway, by way of previewing his long-awaited follow-up to Grand Strategy of the Roman Empire, Professor Luttwak offers in Foreign Policy: Take Me Back To Constantinople, in which he analyzes the military and diplomatic strategies of the Byzantine Empire.
Let's set one thing aside right here. The Byzantine Empire was not the "successor" to the Roman Empire. It was the Roman Empire. We think of Rome as "falling" in 476 when the Emperor's "Master of the Horse," meaning the guy who ran the military for the child-Emperor of the West Romulus Augustulus, decided that things would pretty much work better if he were simply in charge and made lil' Romulus an offer he couldn't refuse -- either abdicate and accept a retirement in a luxurious country estate, or get a sword through his liver after watching the rest of his family get the same treatment. So the "fall" of Rome was really a transition from the Roman system of government to a model more closely resembling an early medieval monarchy. And in fact, the Kingdom of Odoacer was really not all that different than the Empire it displaced.
But Romulus was the Emperor of the West. What about the East? In fact, the cultural, economic, military, and political heart of the Roman Empire had been relocated to Byzantium, renamed and rebuilt as Constantinople, for over a hundred years, by the time of Odoacer's coup d'etat. Constantinople, not Rome, had become caput mundi and the loss of Italy from direct Roman political command was, for the still-existing Roman Empire, actually more of an inconvenience than anything else. The citizens of this Empire called themselves Rhomani, taught their children to quote Virgil (even if Greek was their first language), and were ruled by a line of emperors who traced their line of succession back to Julius Caesar. Even in 1453, as the walls were falling to the cannon bombards of the Ottoman Turks, the Emperor himself plunged in to battle to lead his troops shouting lines from the Aeneid to inspire the soldiers to fight as hard as they could and, if the odds were overwhelming, to at least make a claim for glory. (Chilling.) And where the unified and later Western Empire cleverly deployed its military and political resources to survive through four centuries of daunting challenges, the Byzantines used their military and political resources to last ten centuries longer than their counterparts in the West -- resources which over time became relatively more limited as compared with what the larger empire could have supported.
The immediacy of the example should be obvious. As challenges and circumstances change, so should a dominant power's manner of dealing with them. Luttwak identifies seven principles to Byzantine geopolitical and military strategy, and suggests that the US could learn a few lessons from what they did. Like the Byzantines, our military is very expensive relative to those of our adversaries; like the Byzantines, we hold technological mastery over our adversaries but we hold our blood and treasure much more dearly than they. So the Byzantines adopted a pragmatic, play-them-against-one-another strategy, placing great value in maneuvers in both the diplomatic and military spheres to corner the enemy and only unleashed the full strength of its army (or navy) when the advantage could be certain. Espionage and political subversion of rival states were primary weapons, and questions of "honor" about using tactics like these were not allowed to reach a point that they were allowed to keep the Empire from doing what it needed to do to survive.
Of course, in the end, it was exactly this reaching for a new ally to play off against yesterday's-ally-turned-today's-rival that planted the seeds of the blow which ended the Empire as a geopolitical power, which was inviting the Franks and the Holy Romans into a religiously-based alliance against the Seljuk Turks to recapture Byzantine holdings in Syria and Palestine, using the ostensible goal of recapturing lost Jerusalem as the goal to trigger the religious fervor of the Europeans. Strategically and economically, Jerusalem itself was nearly irrelevant to the Byzantines, but its cultural cachet was useful. Unfortunately, the Europeans didn't play along with the Byzantines and kept the reconquered lands for themselves, and eventually turned on their former allies in a highly questionable military, diplomatic, and ethical decision to sack Constantinople in 1204. While eventually Byzantium recovered and recaptured the urban jewel in its crown, it was never the same after that and by 1453, Rome ended for real.
But that does not mean that we could not learn from the examples set by the Byzantines. There is wisdom in the past, the lessons of history are there for all who have eyes with which to read and minds with which to think. I'll look forward to Luttwak's follow-up book very much.
