|ISIS fighters near Mosul, in the 2014 advance against the city. |
Image source: "ISIS in Mosul, thousands of Refugees Flee," Rodaw.com (9 July 2014).
In a general sense, I am a fan of Bae's approach towards the Sunzi. Recently I read a creative take by Xavier Marquez on the different reasons today's political theorists might study and read the works of 'old' political philosophers like Aristotle, Plato, Hobbes, Locke, et al. As I am quite certain that most of you will find that post more entertaining and intellectually stimulating than this one, I recommend you read that post in full as well.  However, I think Marquez missed a major strain when detailing his 'map' of the modern uses ancient political thought, and it is this approach that Bae practices here. It is also one that I favor. It is a method particularly common in the field of strategic studies (which would explain why both Bae and I embrace it), but others outside the field occasionally adopt it as well. Indeed, I think it was best articulated by a complete outsider to the field. Here is journalist Joseph Sobran explaining why he is so fond of quoting Shakespeare in his columns:
Dogged readers of my columns will observe that I habitually quote a handful of classic writings, chiefly the Shakespeare works, Boswell’s Life of Samuel Johnson, and The Federalist Papers. If those readers suspect that these few masterpieces pretty much exhaust my learning, they are correct.... In Mark Twain’s famous definition, a classic is a book everyone wants to have read, but nobody wants to read. Gulp! But those daunting all-time must-reading lists are a little misleading. It can take years to master a single great author. Much of what we “know” about the classics is what we’ve heard about them in advance, and we may not get beyond their reputations until we’ve read them several times.
Yet the few classics I know thoroughly have been invaluable, even in my work as a journalist. To know a single old book well, even if it hasn’t been canonized as a “classic,” is to have a certain anchorage you can’t get from most contemporary writing.
There are no particular classics, not even Shakespeare, that you “must” read. But you should find a few meritorious old writers you find absorbing and not only read them, but live with them, until they become voices in your mind — a sort of internal council you can consult at any time.
...When confronted with a new topic or political issue, I often ask myself what Shakespeare, Samuel Johnson, Edmund Burke, or James Madison — or, among more recent authors, George Orwell, C.S. Lewis, or Michael Oakeshott — would have thought of it. Not that these men were always right: that would be impossible, since they often disagree with each other. The great authors have no specific “message.”
But at least they had minds of their own. They weren’t mere products of the thought-factory we call public opinion, which might be defined as what everyone thinks everyone else thinks. They provide independent, poll-proof standards of judgment, when the government, its schools, and the media, using all the modern techniques of manipulation, try to breed mass uniformity in order to make us more manageable.To state this idea in another way, we do not read the Sunzi Art of War or Clausewitz's On War (or Plato and Aristotle's works, for that matter) because their authors were infallible, or because they provide theories of politics that have the same sort of scientific validity that the economic theories of folks like Kenneth Arrow or Ronald Coase do, or even because they offer insights into the nature of war and man that cannot be found anywhere else. They were not infallible, their theories have no relation to modern scientific methods, and in a world that has seen wars uncountable fought and talked about by men innumerable, no insight they provide is unique to them alone. However, each offers a coherent conceptual framework that has withstood the test of time. The works produced by this framework can be used as a lens through which any issue can be analyzed. Asking "what would Clausewitz make of this quandary?" is a powerful analytic frame that forces the questioner to consider hard questions about the political context, strategic aims, available means, and enemy intent of the conflict in question. Even if not all of the solutions Clausewitz would submit to his interlocutor are the best ones, the process of thinking through his worldview and adapting it meet the demands of a current crisis will uncover hidden assumptions and point to new possibilities the modern day strategist may not have considered.
The other benefit of this approach is that it combats the tendency to downgrade 'great books' to a series of detached and shallow maxims. Memorizing such maxims is easy, but usually useless. Connecting the famous phrases of any given thinker to the wider web of assumptions, intentions, and arguments found within their corpus requires more work; assessing which of those assumptions and arguments are valid in the context of a contemporary conflict requires even more of it. In my experience this work pays off. However, even if you go through the process and conclude that the framework presented in a great work like the Sunzi has nothing valuable to add to your analysis of a given issue, you will at least walk away with a deeper appreciation for the depth and sophistication of the thinker in question than his popular image as a collection of proverbs would suggest.
This brings us to Bae's treatment of Sunzi. There are some parts of Bae's analysis I agree with wholeheartedly. On other points I am ambivalent. There is one point, however, in which my interpretation of the Sunzi differs strongly from his. To quote:
Perhaps tthe writers of the Sunzi would argue against a direct assault on Mosul, but I do not think this is necessarily true.
Sun Tzu believed warfare was incredibly costly, both in terms of wealth and men. Therefore, he sought to leverage the minimum force to win key decisive engagements, striving to mitigate the heavy price of open warfare. Therefore, Sun Tzu would never approve of the U.S.’s plans to retake Mosul from ISIS in a bloody, direct offensive. When U.S.-Iraqi forces retook Ramadi in January 2016, the city was completely devastated by the ensuing battle. The campaign involved house-to-house engagements and was bogged down by bobby traps and improvised explosive devices (IEDs). Although Ramadi was nominally liberated, the city was essentially decimated. Sabah Karhout, the head of the Anbar provincial council, told The New York Times that “Ramadi is a city of ghosts” and the reconstruction would cost roughly $12 billion. Similarly, a direct offensive on Mosul would be another bloody rendition of a previous strategic mistake. U.S.-Iraqi forces may win on the battlefield, but the wholesale destruction will only feed the narrative of grievance advocated by ISIS. Therefore, Sun Tzu argued, “In the practical art of war, the best thing of all is to take the enemy's country whole and intact; to shatter and destroy it is not so good.” He understood post-war reconstruction would only incur additional costs for the state. One has only to look at the U.S.’s interventions in Afghanistan and Iraq, which total roughly $1.5 trillion in reconstruction efforts, to see the wisdom in his words.
Hence, instead of a direct offensive, Sun Tzu would advocate to “hold out bait to entice the enemy” and then “attack him where he is unprepared, appear where you are not expected.” At the moment, ISIS’s growth and appeal is rooted in the perception that the group is winning the war—fueled by grotesque public displays of violence and a savvy use of social media. Consequently, ISIS has dictated the terms of the war in every aspect, whether in the realm of public opinion or on the battlefield. Therefore, like Clausewitz, Sun Tzu would advise the coalition to attack softer yet strategically important targets such as the ISIS-controlled Omar oil field, which generates roughly $1.7 million to $5.1 million per month for ISIS. By recapturing ISIS-controlled assets, coalition forces would slowly, but steadily apply both political and military pressure on ISIS. Eventually, ISIS would be forced to seek new initiative in an offensive campaign of its own, whether out of logistical desperation or an ill-fated effort to regain its prestige. At that moment, coalition forces can dictate the terms of the engagement in terms of time, place, and manner. Therefore, instead of attacking headlong into a well-defended city, laden with traps and IEDs, the coalition can coax ISIS into a decisive engagement on its terms, best playing to its strengths instead of those of ISIS. 
Let's look at the full context of the 'take the country whole and intact' quotation to understand why I say this. As
The method of waging war holds that it is always best
to take the opposing country intact,
whereas destroying the opposing country is next best.
Taking an opposing army intact is best,
whereas destroying it is next best.
Taking an opposing regiment intact is best,
whereas destroying it is next best.
Taking an opposing company intact is best,
whereas destroying it is next best.
Taking an opposing squad intact is best,For comparison's sake, here is Ralph Sawyer's rendering of the same:
whereas destroying it is next best. 
In general, the method for employing the military is this: Preserving the [enemy's] state capital is best, destroying their state capital is second best. Preserving their army is best, destroying their army second best. Preserving their battalions is best, destroying their battalions second best. Preserving their companies is best, destroying their companies second best. Preserving their squads is best, destroying their squads second best. 
In the piece "The Radical Sunzi" I argued rather forcefully that the key to understand the Sunzi is realizing that it was not written in a vacuum. Much of it was written as a direct response to common attitudes of the time, which depicted war as a ritualized contest of heroes, and the conquest and conduct of war were treated as religious rites. Less time separated the China of the Sunzi from the China of Aztec-style human sacrifice than separated the Greece that produced Thucydides's rationalist vision of war from the Greece that created the honor-driven duels of the Homeric epics. It is difficult to say if the Sunzi simply reflects a change in norms that was sweeping through ancient Chinese society, or if it was actually one of the causes of it. In any case, the change itself is clear. Before the Sunzi violence was justified as a sacral act, and it was employed mostly on for the purpose of personal honor; after the Sunzi violence was justified as a central pillar of statecraft, used mostly on the grounds of cool realpolitik. 
That is the context for the quotation above. When the Sunzi says that the best victory is the victory achieved without recourse to warfare at all, it was attacking the idea that victory and it's glories were the purpose of war. When it says that a country conquered intact is better than a country ravaged by conquest, he is suggesting that ravaging is not a worthy end in and of itself. The unspoken subtext of this passage is that decisions in war should all be judged on the basis of interest (or 'profit,' the Chinese word used here is li 利) of the ruling house. The Sunzi may well have been the earliest voice in recorded history to argue that generals must use cost-benefit analysis to decide on whether or not to embark on any new campaign.
The idea that military force should be used rationally to accomplish national interests; that if possible it is better to achieve those same aims without war; and that every campaign should be subjected to a rigorous calculation of potential costs and benefits are so obvious to modern military planners that most of these ideas are simply assumed, not argued. They do not need to be argued because everyone already accepts them as the baseline for new discussion. When the Sunzi was originally etched into bamboo, however, this was not true. The idea that violence should be used as a rational instrument of policy was a new and radical idea.
The trouble of course with applying Sunzi's advice to measure the costs and benefits of a campaign to our wars today is that the means by which these things are calculated has changed tremendously over the last 2,500 years. The Sunzi argues for capturing territory whole because in the context of the Warring States era it was fairly easy to incorporate territories stolen from other kingdom's into the administrative structures of your own. This was not unique to China; it was true for population-dense, agrarian empires just about everywhere. Before the industrial revolution the fastest way to increase your tax revenue and national wealth was to take it from others. Conquest paid--if you were careful about how you went about conquering. The Sunzi implores its readers to ensure that their conquests are paying more to the treasury than they are sucking from it.
The rest of the passage--which Bae does not quote--develops this theme. Enemy soldiers should not be captured and sacrificed, nor killed en masse. Why? Because they could be incorporated with ease into the armed forces of their conquering enemy, or barring that, sent home to work their farms and contribute to the tax base.
You can probably see how difficult it is to apply the Sunzi's advice directly to operations in Iraq. Iraq is a money sink. For the United States of America this would be true even if Mosul was taken without a brick out of place. Likewise, the men fighting for ISIS are not likely to become recruits in the American military machine. This will be true regardless of how many of them survive the coming battle for Mosul. In other words, the Sunzi's economic calculations simply don't work in this context, and it is not useful to apply them literally to the campaign against ISIS.
The broader principle behind the Sunzi's calculations may prove more useful. The Sunzi's advice, when boiled down to its essence, is that no armed power should squander its resources on campaigns that do not materially advance its interests. The writers of the Sunzi would thus have little patience for the "bomb the sand till it glows" types, correctly seeing such a policy as a form of armed virtue signaling, the very attitude the Sunzi was originally written to combat. But this does not mean the Sunzian strategist would shy away from massive destruction and violence. What matters to the Sunzian thinker is greatest return for smallest investment.  The only reason the Sunzi argues against laying waste to your enemies lands is because it recognizes that doing so usually reduces the material advantages a commander might gain from waging war in the first place.
But what if the amount of destruction wrecked did not reduce or increase the material gains the victor could claim? In such a scenario, there is nothing in the Sunzi's philosophy that prohibits bloody, costly battles. The Sunzian strategist looking to maximize America's profit (li) in Iraq might conclude that it is in the United State's best interest to fight in such a way as drag as much of ISIS's manpower into the battle as possible. The goal of such a campaign would be to 1) leave ISIS's millenarian ideology and sense of "spirit" broken and discredited 2) exhaust and deplete the groups that give active support to ISIS so that even if Salafi-Jihadist thought doesn't lose its luster in defeat, the groups in question will not have the material means to support it in the future. If a drawn out siege of Mosul could accomplish those things then from a Sunzian perspective it would be worth it. This is because for the United States, maximizing profit in the cold realist sort of way the Sunzi advocates means using force so effectively that the United States does not have to return to Iraq again. If it is not possible to use military force to this effect in the fight against ISIS, the Sunzian strategist would likely advocate leaving the region entirely, using force only where there are clear material benefits for doing so.
I do not know if I fully agree with the Sunzian approach here. I've laid out my preferred course of action in the post "The Fight Against ISIS--a Few (Unorthodox) Points For Discussion," and refer readers curious about my views on the question there. However, the purpose of this post is discuss the Sunzi. Whether or not you agree with the policy options presented above, this is probably the closest articulation of a true Sunzian approach we can get to.
 Sebastian Bae, "In the War With ISIS, Don't Forget About Sun Tzu," Strategy Bridge (15 April 2016).
 Xavier Marquez, "Does the History of Political Thought Matter," Abandoned Footnotes (11 July 2011).
 Joseph Sobran, "Reading Old Books," Sobran's Real News of the Month (or. published 6 April 1999).
 Bae, "War With ISIS,"
 Victor Mair, trans., The Art of War: Sunzi's Military Methods (New York: Columbia University Press, 2009), 84-85.
 Ralph Sawyer, The Seven Military Classics of Ancient China, 2nd ed (New York: Basic Books, 2009), 159.
 For more on this see the post referenced, T. Greer, "The Radical Sunzi," Scholar's Stage (2 January 2015) and Andrew Seth Meyer, "Introduction," in The Dao of the Military: Liu An's Art of War, trans. Andrew Seth Meyer and John S. Major (New York: Columbia University Press, 2012),
 The Sunzi generally recommends manipulating shi (势）, usually translated as 'the configuration of power,' or 'strategic momentum,' in order to do this. Indeed one could argue that shi is ultimately about being able to do the most with the least force available. That is a topic best reserved for its own post, however.