"Hybrid War: Old Concept, New Techniques"

An article at The Small Wars Journal. Although they don't acknowledge 4th generation war theory, the article does have this to say:

While the means by which state and non-state actors conduct hybrid war today have changed, the fundamental principle of utilizing a combination of conventional and irregular methods to achieve a political objective is consistent with older forms of conflict.  This blending has historic examples in the American Revolution with George Washington’s Continental Army and robust militia forces; the Napoleonic Wars where British regulars challenged French control of major Spanish cities, while Spanish guerrillas attacked their lines of communication; and the Arab Revolt where the British Army combined conventional operations in Palestine with irregular forces under British operational control.[i]  However, despite having its roots in history, modern hybrid war has the potential to transform the strategic calculations of potential belligerents due to the rise of non-state actors, information technology, and the proliferation of advanced weapons systems. 

The unipolar moment that has persisted since the fall of the Soviet Union has given rise to an international system in which unconventional challenges to the idea of traditional state-on-state war are increasingly prevalent.  The preponderance of American military power has tempered conflicts in Southeast Asia, the Indian subcontinent, and the South China Sea, but has given rise to a method of war that attempts to leverage the weaknesses of conventional military structure.  Where wars traditionally have regular and irregular components in different areas of operation, modern hybrid war has the tendency to combine these aspects.  Modern hybrid war practitioners apply “conventional capabilities, irregular tactics and formations, and terrorist acts including indiscriminate violence, coercion, and criminal activity” simultaneously.[ii]  Under this model, war takes place in a variety of operating environments, has synchronous effects across multiple battlefields, and is marked by asymmetric tactics and techniques.[iii]  These tactics are difficult to defeat for militaries that lack the flexibility to shift mindsets on a constant basis, especially since the interconnected nature of modern society is such that hybrid war takes place on three distinct battlefields:  the conventional battlefield, the indigenous population of the conflict zone, and the international community.[iv] 

Major powers have historically sponsored irregular fighters and non-state actors in the execution of broader military campaigns, and modern examples such as Iranian support to Hezbollah and other Shia militant groups are continuations of these policies.  The Israel-Hezbollah War of 2006 showed that although the concept of hybrid war in this fashion is not novel, some of the sophistication and lethality of non-state actors, along with their ability to persist within the modern state system, is a new occurrence.

Underlines added.