The military historian William S. Lind introduced the concept of generations of war in a seminal speech he gave in Quantico, Virginia in 2000, and later published as The Four Generations of Modern War. The concept has been widely adopted and further developed by a number of other commentators, including Martin van Creveld (The Transformation of War), John Robb (Brave New War, 2007), T.X. Hammes (The Sling and The Stone), and Daniel H. Abbot and his co-writers (The Handbook of Fifth-Generation War), among others.
The exact nature and number of the generations of war are hotly debated, with every author listed above and many others using the terms differently. To a first approximation, however, there are two schools of thought, called GMW (Generation of Modern War) theory and xGW (X Gradient War) theory.
The GMW school is led by Lind himself and more-or-less accepted by Creveld, Robb, and Hammes. According to GMW theory, the generations of war have a progressive sequential emergence over historical time. Just as each human generation emerges from a previous human generation, each generation of warfare emerges from the previous generation. Specific social and technological conditions spawned the first generation of warfare (1GW). The second generation of war (2GW) then evolved as an adaptation to 1GW. The third generation of war (3GW) developed to defeat 2GW. Finally, a fourth generation of war (4GW) was spawned to oppose 3GW. Pursuant to this formulation, Lind believe it is premature to outline the fifth generation of war (5GW), as the wars of the fourth generation are still being fought. Robb and Hammes, however, have alluded to 5GW as the next generation to emerge in the historical sequence.
The opposing xGW school is found in the aforementioned Handbook of Fifth-Generation War, where theorists such as Daniel H. Abbot, Adam Herring and F.E. Younghusband have developed it. The xGW school rejects the notion that generations emerge in an unfolding sequence. Indeed, xGW theory rejects the word “generations” itself, preferring to use G to stand for “gradients.” Each gradient reflects a centralizing principle about how to deploy force. Certain gradients may have emerged at certain moments in time, but any gradient of war can be deployed by any type of adversary. The gradients of war might be likened to the moves in scissors-paper-rock. New moves might be discovered over time (dynamite, water) but once discovered all moves remain playable. According to the xGW theorists, 5G warfare is not just a theoretical future possibility — it is already upon us.
The Generations of War as I See Them
In developing my own theories on the matter, I have come to agree with the GMW theorists that war should be understood in generations rather than gradients, with the generations unfolding in a sequence of innovation and adaptation. However, I am persuaded by the xGW theorists that 5GW is already happening. Then I go beyond them. I believe 6G warfare soon will be here, and that preparation is already being made to establish 7G warfare to counter it.
Here, then, are the generations of war as I see them:
1GW - Concentration of Mass
First-gen warfare developed in the aftermath of the Thirty Years War, when the modern nation-state began to dominate warfare. 1GW is characterized by the state’s ability to mobilize mass formations which are regimented with strict discipline and orderly deployment. It was made technically possible by the development of inexpensive, reliable, short-range bayoneted muskets. 1GW wars include the Seven Years War and the Napoleonic Wars.
2GW - Concentration of Firepower
To counter mobilized masses deployed in rank-and-file formations, second-gen warfighters introduced the use of concentrated, synchronized fire to destroy the enemy. 2GW was made technically possible by the development of indirect artillery with explosive shells, long-range rifled firearms, and (eventually) machineguns.
The US Civil War began as a 1GW war but the new weapons used ended up making it the seminal 2GW war. The First World War was the definitive 2GW war, as concentrated firepower made 1GW offensives impossible.
3GW - Maneuver
To counter the massed fires of 2GW armies, third-gen warfighters began to use what has been variously called “infiltration tactics,” “blitzkrieg,” and “maneuver warfare.” Whatever its name, it relies on speed and shock to disrupt and decohere the enemy’s centers of gravity such as supply chains, ammo dumps, and headquarters.
3GW was made possible by mechanization, which enabled attacking troops to reinforce success more quickly than defending reserves could be deployed by railroad. 3GW tactics were first used by German stormtroopers in the last year of the First World War, and then were adopted throughout the Wehrmacht in the Second World War. It remains the doctrine of the Bundeswehr today. The Israeli Defense Forces adapted and used 3GW in 1967 and 1973, while the US Marine Corps adopted 3GW as its doctrine in the 1980s.
The Generation that Wasn’t
At the end of WWII, the United States demonstrated the power of nuclear weapons. Since they came at a time when the whole world had just been waging total war, it seemed to early theorists that nuclear weapons would be used in the next conflict, and both the US and USSR accordingly reconfigured their forces for an atomic battlefield. But, as more and more states gained access to more and more powerful weapons, the would-be belligerents increasingly found themselves in an equilibrium of mutually assured destruction (MAD). No one could use nuclear or conventional forces without risking utter annihilation. MAD brought a temporary end to state-on-state warfare between the great powers.1 Had things developed differently, nuclear conflict might have become the fourth-generation of war, with anti-ballistic space weaponry (Reagan’s SDI) as the fifth-generation adaptation. Because that didn’t happen, the next generation of war evolved in an unexpected direction.
4GW - Networked Insurgency
To counter the devastating disruption caused by 3GW armies, fourth-gen warfighters realized they had to distribute rather than concentrate their mass and eliminate their vulnerable centers of gravity. Therefore, 4GW would be waged by horizontally connected networks of insurgents who could not be destroyed by massed fire nor disrupted by lightning strikes on key areas.
Since, by definition, a nation-state will always have key areas to defend, a nation-state cannot use 4GW. But 4GW can be used against states by non-state actors, such as rebels, terrorists, criminal gangs, rural bandits, and pirates.
4GW was made possible by continuing advances in small arms, explosives, and other weapons, but even more so by advances in communications and information technology. The “Information Age” has ushered in a highly connected global era of just-in-time inventory, smart networks, energy-efficient grids, and other systems that Nassim Taleb has rightly dubbed fragile. The highly-connected networks, and the fragility they create, are both exploited by 4GW warfighters. Their swarm-like attacks can damage the economy and undermine the legitimacy of the state in the eyes of those it is supposed to protect.
The Chinese Revolution and Vietnam War represent early efforts towards 4GW, but the generation began in earnest with the terror attack on 9/11 and the subsequent insurgencies in Iraq, Afghanistan, and other trouble spots throughout the globe.