The “Side-Principal” Rule And Unrestricted Warfare In Chinese Military Doctrine


In 1999, two colonels in the Chinese Army, Qiao Liang and Wang Xiangsui, published a treatise that would heavily influence Chinese military planning for the following decades.  The book was called Unrestricted Warfare.  Its central theses were these:

  1.  Future wars would be fought across the entire spectrum of human affairs, down to the individual level.
  2.  The United States would be China’s principal adversary in any future conflict.
  3.  Alternative methods of “fighting,” such as international law, economic warfare, disruption, trade conflict, currency manipulation, cyber war, terrorism, and population movements, could be just as effective as traditional engagements with military weaponry.
  4. American military planners take too narrow a view of the possibilities of future conflicts.  They place too much emphasis on hardware and technology, and not enough on social, moral, political, and economic factors.

An English translation of Unrestricted Warfare was soon produced.  It is not precisely known to what extent the book represents Chinese policy, or whether it is simply an intellectual exercise by two ranking military officers.  Regardless, it makes for sobering reading.  The authors have an impressive grasp of military history and base their conclusions on reasoned arguments, rather than on ideological imperatives.

Many military writers and theorists like to coin new terms and invent new “doctrines,” or herald the arrival of some “new generation” of warfare.  On closer inspection, most of these “new doctrines” are simply old ones presented in new packaging.  How many different names can we give for 21st century warfare?  How many times can we make the point that future wars will take place across every sphere of human activity?  How many times can we make the point that non-military means can be more effective than military ones?

Not enough, apparently.  For no matter how many times the point is made, the lesson always seems to elude those in positions of authority.  Perhaps it has always been this way.  The chaos of conflict creates its own logic, and has its own unique method of deployment.  It can be predicted only with limited accuracy.


I believe that Unrestricted Warfare is different, however.  It is rare window into the culture of Chinese military theory, one which does not open with frequency.  It should be studied carefully by those interested in the strategic environment which the United States finds itself in the early decades of the 21st century.

The “Side-Principal” Rule

One of the central concepts in Unrestricted Warfare is something which the authors call the “side-principal rule.”  It has not received the attention it has deserved in the West; one can barely find it discussed at all.  Yet an understanding of this concept is critical to grasping the essence of Unrestricted Warfare.  We will discuss it here.  (The quotations below appear in pp. 157-169 of the translated text.)

What is the side-principle rule?  It is essentially a rule that allows us to understand the relationship between what is “dominant” and what is “the whole” in any integrated system.  The authors begin by using an analogy from Chinese grammar:

In Chinese grammar, there is a basic sentence structure. This structure divides a sentence or phrase into two parts, the modifier and the center word. The relationship between them is that of modifying and being modified, that is, that the former modifies the latter and determines the tendency and features of the latter. Put more clearly, the former constitutes appearance, and the latter constitutes the organism. We usually determine the difference between one person or object with another person or object not according to his (its) existence as an organism or mechanism but according to his (its) appearance and look.

From this perspective, relative to the center word, the modifier should, to a greater extent, be considered the center of a sentence or phrase. For instance, red apple. Before being modified by “red,” apple only refers to a kind of fruit in general and is thus general in nature. But, “red” gives this apple a specificity that makes it possible to determine it to be “this one.” Obviously, “red” plays a significant role in this phrase.

Also, for instance, special economic zone. Without the word “economic”, special zone is only a concept of geographical division. When modified by “economic,” it acquires a special character and orientation, becoming the point of support for the economic lever used by Deng Xiaoping to reform China.

This structure is a basic mode in Chinese grammar:  the side-principal structure. 

But the authors are not just making a grammar exercise, we are reminded.  This “side-principal” concept has applicability far beyond language:

We do not intend to arbitrarily juxtapose war with grammar, but only intend to borrow the term “side-principal” to enunciate the deepest core element of our theory. For we believe this side-principal relationship exists in a big way in the movement and development of many things, and that in such a relationship the “side” element, instead of the “principal” element, often plays the role as the directing element. For the time being, we describe this role as “modification by the side element of the principal element” (note: this is not the original meaning of the side-principal structure as a grammatical device, but an extended meaning as used by us).

For instance, in a country, the people are the principal entity, while government is the directing element of the country; in an armed force, soldiers and middle and lower-level officers constitute the principal entity, while the command headquarters constitute the directing element of the armed force; in a nuclear explosion, uranium or plutonium is the principal entity, while the means of bombarding them constitute the directing element for triggering chain reactions; in a Southeast Asian-style financial crisis, the victim countries are the principal entities, while financial speculators are the directing element generating the crisis.


The authors then go on to assert that a definite mathematical relationship exists in “side-principal” scenarios:

As shown through discussions above, this side-principal structure is an asymmetrical structure. Thus, the relationship between the side element and the principal element is an unbalanced relationship. On this point, the situation is very similar to that regarding the rule of the golden section: 0.618 and 1 form an asymmetrical structure and an unbalanced relationship.

We are fully justified in regarding it as another way of stating the side-principal formula. For, in this side-principal structure, what is important is the side element, but not the principal element. This is also true with the rule of the golden section. What is important is 0.618, but not 1. This is the common feature of the two. Laws tell us that two things with similar features must follow some similar rules. If there is any common rule governing the golden section and the side-principal structure, it should be the following :

0.618 = deviation toward the side element

This same mathematical relationship can be found in military affairs as well, we are told:

Among the many internal elements comprising a thing, there must be a certain element which assumes a prominent or dominant position among all the elements. If the relationship between this element and the other elements is harmonious and perfect, it will be in accord with the 0.618:1 formula in some places and, also, in accord with the side-principal rule. For, here, “all the elements” constitute the main body, that is, the principal element; the “certain element” serves as the directing element and is thus the side element. Once an object has acquired specific purposefulness, the side element and the principal element will form a dominant-subordinate relationship.

When two bulls fight, the bulls constitute the principal element, while the horns constitute the side element. When two swords are pitted against each other, the swords constitute the principal element, while the edges constitute the side element. It is very clear which is dominant and which is subordinate. When the purpose is changed, a new dominant element will emerge and replace the old dominant element and form a new side-principal relationship with all the existing elements. Grasping the relationship between the dominant element and all the elements in an object is tantamount to grasping the essence of the rule of the golden section and the side-principal rule.

On the basis of such an understanding, we can quickly establish five most important relationships among all the complex relationships of war: the dominant weapons and all the weapons; the dominant means and all the means; the dominant force and all the forces; the dominant direction and all the directions; and the dominant sphere and all the spheres. The relationship between the five dominant elements and all the elements in the five areas basically represent the side-principal relationship which exists in wars in a widespread manner.

Finally, the authors cap their arguments with this summation:

Whether an action is a pure war action, a non-war military action, or a non-military war action, any action of a combat nature will entail an issue of how to accurately select the main direction of operation and the main point of attack, that is, to determine your main orientation in view of all the factors of the war concerned, the battlefields, and the battle fronts. This is the most difficult issue even for all those commanders who are in control of good weapons, a multitude of means, and sufficient manpower.

However, Alexander, Hannibal, Nelson, and Nimitz as well as Sun Wu and Sun Bin of ancient China were good at selecting main directions of attack which would surprise enemy forces completely. Liddle-Hart also noted this point. He referred to the approach of selecting the line of least resistance and the direction of action least expected by the enemy as the “indirect strategy.” As the arena of war has expanded, encompassing the political, economic, diplomatic, cultural, and psychological spheres, in addition to the land, sea, air, space, and electronics spheres, the interactions among all factors have made it difficult for the military sphere to serve as the automatic dominant sphere in every war.

War will be conducted in non-war spheres. This notion sounds strange and is difficult to accept, but more and more signs indicate that this is the trend. In fact, even in ancient times, war was not always confined to one single sphere. Lian Xiangru’s diplomatic battle of “returning the jade in an undamaged condition to Zhao” and the virtual war conducted by Mo Zi and Gongshu Ban were classical examples of winning or precluding a war with non-military actions. This method of resolving the problem of war through actions in multiple spheres should give insights to people today.

The era of comprehensive use of highly developed technologies has provided us with much greater room for applying wisdom and means than ancient people, so that people’s dream of winning military victories in non-military spheres and winning wars with non-war means can now become reality.

If we want to have victory in future wars, we must be fully prepared intellectually for this scenario, that is, to be ready to carry out a war which, affecting all areas of life of the countries involved, may be conducted in a sphere not dominated by military actions. It is now still unknown what weapons, means, and personnel such wars will use and in what direction and sphere such wars will be conducted.

What is known is one point, that is, that whatever the mode of warfare, victory always belongs to the side which correctly uses the side-principal rule to grasp the relationship between the “dominant” and the “whole.”

Are the authors correct, or is this “principal” a Pythagorean delusion that the authors have become fixated with?  I believe that there is much merit to this idea, although I do not have specific studies in system dynamics at hand to support my belief.  Perhaps even this is not the point.  A look at Chinese military and economic policy from the past twenty years suggests that the political leadership in Beijing has grasped, and is making use of, the doctrine of unrestricted warfare as laid out in this book.

Seen from this perspective, many events from recent headlines become clearer.  The attempt to dig a canal in Nicaragua, the unapologetic manipulation of the yuan for trade advantages, unrestrained “product dumping” to gain a foothold in new markets, the use of immigration as a force multiplier, cyber hacking, etc.:  all of these practices, and many more like them, point to an embracing of the ideas laid out in Unrestricted Warfare.



For more about strategic thinking and other related ideas, read Thirty-Seven.