The Grand Strategy of the Roman Empire

Luttwak's controversial thesis on interpreting the pre-Byzantine Roman Empire's geopolitical strategies from roughly the early Empire to Constantine as 3 broad systems of governance and frontier defense. (The Byzantine Empire's own long and intricate militarized history is dealt with by Luttwak in a separate later book, unsurprisingly titled, The Grand Strategy of the Byzantine Empire, which in general I found far more interesting as the Byzantine Empire is considerably underrated & ignored.) Not being a Roman historian or archaeologist, I can only say of the controversy it didn't strike me as obviously wrong or making major errors, although the thesis appears most strained when Luttwak tries to discuss the third system, the late empire after the third century crisis, as forming a coherent strategy of partial defense-in-depth.

What most interesting about the discussion of the first two stages is the extent to which Luttwak takes what you might call a "Chinese" focus, by emphasizing the relative smallness of the Roman military compared to its vast territories, exploiting a "use the near barbarian against the far" strategy of neighboring (relatively) barbaric vassal states to defend its borders and provide strategic depth - states like King Herod.

In most accounts, these vassal states are treated almost as comedies, literal side-shows to the real business of state and war in the Roman Republic/Empire itself. Luttwak sees the border function as critical to removing the need for a large military spread across many small far-flung border forts & detachments, allowing a concentration of soldiers into the handful of enormous Roman legions which could shatter any enemy in their way while being deployable without denuding any frontiers, giving them credibility as deterrents - and, "the paradox of strategy", by such deterrence, ensuring they were only occasionally needed and leaving the Empire's military deterrence flexibly deployable. Meanwhile, the neighboring vassals would gradually urbanize & Romanize thanks to constant influence from the Empire and the benefits for development of the Pax Romana, and eventually, their incorporation into the Empire would be a fait accompli and mere change of labels. Areas too impoverished, dried, or indefensible would not develop, and would be bypassed. The occasional revolts or invasions could be swiftly suppressed by the nearest legion marched or sailed into place. Thus, the Empire could enjoy a small cheap but invincible military and steady expansion into rich lands, with the borders eventually stabilizing at their outer limits of cost-benefit, and the golden age of the Empire. Far from being amusing anecdotes of ancient legalistic squabbling, the vassals were critical for freeing up legions and a necessary transition phase.

The similarities with Chinese grand strategy are unmistakable: the same tactics reappear like the use of bribes, honorary titles and statuses, intermarriage with generals or aristocrats, use of neighboring vassal states to insulate & control further enemies, and the gradual expansion of the formal boundaries of the Empire with the expansion of the Han population-culture-plex, economic/agricultural development of once remote regions, and incorporation/suppression of indigenous populations.

Whether this is really a "grand strategy" in the sense of a consciously enunciated strategy even to the degree of Chinese literati debating tactics & barbarian-quelling strategies in memorials to the emperor is largely unanswerable, as so much Roman material fails to survive & such strategic considerations might be expected to be considered key state secrets. Luttwak can't make much of a case one way or another, and it would be reasonable to suppose that the fact that the many decisions & battles & fortifications look fairly coherent reflects local decision-making and narrowed choices and trial-and-error reaching fairly optimal outcomes, an emergent order as in so many things. It might be better to take this book as a sort of "how I would do it", in the manner of a strategy game walkthrough like an account of a game of Europa Universalis; Luttwak's opinions are usually interesting and amusingly expressed, so it is certainly not a waste of time.