The Tasks of Imperial Militaries

Soldiers often say that the military's main jobs are killing people and breaking things. By extension, we might say that an imperialist's main job is channeling slaughter and destruction in directions that help the empire—basically what Clausewitz had in mind when he called war “the continuation of policy with the admixture of other means.”^[353] Looking at the 50-odd examples in these volumes, three main channels seem to be particularly useful to empires.

3.1. Conquest

The first of these is conquest. Nearly all empires begin in military conquest and feed on a diet of it. To be sure, empires do not have to begin or grow this way; empire by invitation, in which one group willingly surrenders some or all of its sovereignty to foreigners, is also possible. However, in practice this rarely happened, except when it seemed like the lesser of two evils, with the alternative being violent conquest by a stronger empire. Sometimes this reality is very clear, as when many Greek city­states voluntarily joined the Persian Empire in 481 bce to avoid attack, and when many of the same states accepted Athenian dominance from the 470s on, again as a way to avoid Persian conquest. Similarly, in June 1940 the French and British empires seriously discussed merging, despite centuries of hostility, as an alternative to being forced into Hitler's Reich.

Even when fear of conquest was less immediate, it often provided the subtext for empire by invitation. The most striking cases—even if neither fits squarely into our definition of empire—are probably the decisions by the 13 ex-British colonies in

North America in 1787 and six long-time rivals in Western Europe in the 1950s to hand over much of their sovereignty to federal governments. Even though no one invaded anyone in either situation, both decisions were heavily influenced by fear of external aggression (from the British, French, and Spanish empires in the eight­eenth century and the Soviet in the twentieth) and memories of terrible recent wars.

Empire by invitation can take many other forms, although all in the end seem to come back to conquest. Dynastic marriage and inheritance can create empires without bloodshed, but the unions nearly always end up having to be defended— or are destroyed—by force. The Angevin Empire is a good example, assembled by inheritance in 1154, but almost constantly at war until decisively defeated at Bouvines in 1214; and Charles V's Habsburg Empire, the fruit of countless clever marriages and timely deaths, dragged much of Europe into violence after 1519. Empire by inheritance is certainly not empire by conquest, but it tends to turn into empire by war anyway.

Yet another alternative is what historians often call “informal empire.” In the most famous case, despite never having been conquered by Britain, much of the nineteenth-century Middle East and Latin America were so thoroughly at the City of London's mercy that their sovereignty was fatally compromised. However, Britain's informal empire was created by economic means as an adjunct to the formal em­pire that it created through conquest, and empire by invitation was unimaginable without an accompanying empire by coercion. The same applies to the networks of dependent client kingdoms that imperialists have been using as an inexpensive ad­junct since the Third Dynasty of Ur in the twenty-first century bce.

Every empire in this book began and expanded through conquest. Plenty of empires used non-military methods, too, but we can probably conclude that mil­itary organizations able to conquer other polities are always necessary, even if not always sufficient, for empires.

3.2. Managing External Relations

After conquering an empire, the second main task for military organizations is in managing its external relations. In an essay written in 1804, Clausewitz concluded that there are really only two kinds of war, aiming “either to totally destroy the enemy...

These categories overlapped and came in an astonishing variety of forms. At one extreme are campaigns like those of China's Wudi emperor, who repeatedly sent armies hundreds of thousands strong out into the steppes in the 130s-120s bce to terrorize the Xiongnu nomads into stopping raiding his border provinces; at the other, the kind of “savage wars of peace” memorialized by Rudyard Kipling,¹² some­times undertaken by just a handful of soldiers, sailors, or airmen (including those piloting their craft remotely) and often leaving little or no trace in the historical record. Most empires, including the most modern, have been engaged almost con­stantly in conflicts at various points on this spectrum.

The place where force is applied most constantly to the management of external relations, though, is usually border control. Empires need to protect taxpayers living near their frontiers from being robbed by outsiders, usually want to con­trol who comes and goes across these frontiers, and would often like to make an­yone trading across the frontiers pay for the privilege (which, of course, also means chasing down smugglers who evade these costs). As a result, empires regularly sta­tion much of their military along their borders and often spend heavily to provide them with walls, forts, and fleets to make their jobs easier.

3.3. Managing Internal Relations

Finally, empires also use military organizations for managing internal relations. Often this means tasks that modern states and empires hive off functionally spe­cific gendarmeries whose right to use force is strictly limited; but in premodern times, armies and navies were often the only tools available for overcoming resist­ance to the government, whether that came from unruly crowds, organized crime, or uprisings involving millions of subjects.

It might almost be quicker to make a list of functions that military organizations don’t perform for empires than of those they do perform. Basically, pretty much any task we can imagine has been carried out by the military in some empire or an­other. However, at the level of abstraction required by this short chapter, conquest

and managing external and internal relations do seem to cover the major roles. The bottom line, though, is that no empire can function without military organizations.

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