Like the poor, guerrilla armies have, it seems, always been with us. From the nomadic rebels who brought down the Roman Empire to the Internet-savvy, plane-exploding jihadists who triggered America's ill-conceived "global war on terror," irregular forces are a constant factor in the history of warfare. And fighting them has become tougher than ever.
Plenty of literature gives advice on how to beat such maddening foes. Max Boot, a neoconservative American military historian, has done something different. Invisible Armies is a narrative history of guerrilla warfare and terrorism (its less effective cousin), ranging from what he describes as its origins, in bringing down the Akkadian empire in Mesopotamia in the 22nd century B.C., to the present day. The author moves quite quickly over the first 4,000 years or so and only really gets going in the 18th century, with its revolutionary wars of independence.
Among the many "liberal" insurgencies he considers are the American revolution; the struggle against Napoleon in the Iberian peninsula; Greece's war for independence against the Ottomans; the wars of unification in Italy and various uprisings against colonial powers, such as the slave revolt against the French that led to the foundation of the Republic of Haiti. In the 20th century Boot examines the impact of irregular forces in the two world wars (among them those led by the eccentric English officers T.E. Lawrence and Orde Wingate); the contribution to insurgent theory of Mao Zedong's seminal work On Guerrilla Warfare, gleaned from his experiences in the Chinese civil war; the very different French and British responses to rebellions against their fading empires; the "radical chic" revolutionaries of the 1960s and the rise of radical Islamism.
If this sounds a bit like a list, it is because of the way the book is organized. Boot picks a theme, for example, "The End of Empire," and then hoovers up into that section all the conflicts that can be made to fit that description. Each one gets a few pages of lively narrative and a brief analysis of why one side prevailed over the other. The formula works rather well. Even when the author is rattling through fairly familiar territory, such as the failures of the French against the Vietminh, he usually finds something fresh or pithy to say.
Take, for example, Vo Nguyen Giap, the brilliant Communist general who succeeded in expelling first the French and then the Americans from Vietnam. Giap closely followed the teachings of Mao in planning a three-stage struggle — first "localized guerrilla war," then "war of movement" and finally "general uprising" — which he waged with a three-tier force of village militias, full-time guerrillas and a regular army.
But where Mao was always cautious to avoid confrontations with more powerful forces, Giap's tendency to "roll the dice on premature offensives" in 1951, 1968 and again in 1972 could have proved fatal each time had it not been for the psychological and political frailties of the other side. In guerrilla warfare, what matters most is the ability to shape the story, not the facts on the ground. This is how guerrillas are able to win wars even as they lose battles.
Because insurgencies pit the weak against the strong, most still end up failing. Between 1775 and 1945 "only" about a quarter achieved most or all of their aims. But since 1945 that number has risen to 40 percent, according to Boot.
Part of the reason for the improving success rate is the rising importance of public opinion. Since 1945 the spread of democracy, education, mass media and the concept of international law have all conspired to sap the will of states engaged in protracted counter-insurgencies. In the battle over the narrative, insurgents have many more weapons at their disposal than before.
Boot does not conclude that counter-insurgency in the 21st century is a losing game. But to prevail requires an understanding of the game's rules. He is a powerful advocate for the so-called "population-centric" approach pioneered by the British during the 12-year postwar Malayan Emergency, which lasted until 1960, and rediscovered by American generals such as David Petraeus and Stanley McChrystal in Iraq and Afghanistan only after things there had gone disastrously wrong.
The first principle is to abandon conventional military tactics. "Clear and hold" beats "search and destroy." To defeat an insurgency you must provide enough security for ordinary people to live their lives.
The second is that legitimacy is vital for both sides: corrupt or excessively violent governments will always struggle, but so too will guerrillas who terrorize their own people. The third is staying power. Firepower is no substitute for patience and boots on the ground. The people you need on your side must believe that you are in it for the long haul.
The fourth is that most counterinsurgency campaigns abroad are lost at home. Liberal democracies have short attention spans, low tolerance for casualties and other calls on their cash. Unless voters believe that an intervention is necessary for their own security they will quickly withdraw support for it.
All of which explains why things are not going well in Afghanistan. The population-centric approach — and the troop surge needed to realize it — came late in the day and with a foolishly rigid deadline. The Afghan government has some popular legitimacy, but not enough in the places where the insurgency is resilient. Nor has it been possible for American forces to deny the Taliban their sanctuary in Pakistan: insurgencies with outside support are much harder to beat. Voters in America and Europe are not prepared to spend any more blood or money on what most presume is a lost cause. Few think that what happens in Afghanistan will affect their own safety.
Counterinsurgency may be out of fashion again, but it remains necessary to know how to do it. Boot offers a timely reminder to politicians and generals of the hard-earned lessons of history.
© 2013 The Economist