There is an old saying: “the law of averages”. It does not mean anything specific. Is there such thing as a “law of advantages”?

In the language of economists, there is, essentially, and it underpins some analyses of international affairs too, but not usually amongst historians and international relations scholars. Why is that?

Different disciplines use different terminologies. Often, they are characterised by different reasoning too. Students of the humanities focus on human agency. So too do many commentators.

I read a British author in recent times who suggested that British foreign policy has always been principled precisely because it has a humanist focus, refusing to stoop to manipulating economic factors to gain, or maintain, an edge. Perhaps the author sincerely believed that.

I do not know why Ireland’s foreign affairs department dropped the term “trade” from its title last year, but perhaps the decision was rooted in a parallel belief, or projection.

Some would say national interests are always conceived primarily in terms of military realpolitik. Yet nearly all states, ever since what historians term the “early modern” period (c.1550-c.1800), have existed on credit. Without bank credit, there is no state. Without competitive efforts by banks to either influence or adapt to financial markets, there would be no banks.

If banks or states are not willing to do business with a particular state that state may go out of business. Where does human agency come into this? What tools do humans use so that a state can exist, survive or thrive? Is the answer not obvious? Perhaps. But the answer is not simple either because of the way many conceive of economic and military affairs as separate spheres.

For me, perhaps the most interesting aspect of the historiography of early modern Europe was new studies of warfare; namely, those that viewed war in an economic and social light. In feudal societies, landowners mobilised armies using their authority over their tenants. For the duration of a war, that mobilised army was given the right to everything: food, clothes, fuel, medicine, people, you name it. If they wanted it (or claimed to need it), they took it and the non-enlisted had no right to complain, even if they were impoverished or starved. If you didn’t want to starve, you probably would have had to enlist too. Husbands lost wives and wives lost husbands, one way or another. Wars may have benefitted states, but they left societies in chaos. As the news may remind us, they still do. That is why a permanently constituted, or standing, army was considered a potentially tyrannical imposition by the end of the early-modern period. Competitive sports have sometimes been described as modern substitutes for competitive battles; in short, cheering football teams instead of cheering gladiators. If so, there may be reason to welcome that sublimation.

Nineteenth-century revolutionaries were anti-feudal – that’s their interesting side – although their willingness to consider using violence to undo a system made them controversial, like forming a new army in opposition to an old one and so risking chaos. Another paradox was that in asserting that they did not want to be taken advantage of by the old order, they were effectively imagining a new order that would allow them to take advantages. Are such plays for advantage always part and parcel of human society?

I remember in studying 1880s Ireland how the purposeful shunning of individuals – including an infamous Captain Boycott (the event that gave birth to the verb “boycott”) – was deemed a highly controversial implementation of an unwritten law, creating a rule to put others out of business. Even some self-proclaimed revolutionaries deemed it “immoral”, ironically making them seem much more conservative than many ordinary members of society. But boycotts happen all the time, not just among historic Irish peasantries. As the news may remind us, if a new regime in Afghanistan is boycotted, in an attempt to put it out of business, will it be an act of high finance with the politicians in tow, or are the instruments of high finance and statehood one and the same?

Economic theories of comparative advantage or absolute advantage may govern policies more than most commentators, including historical commentators, are either given to understand or inclined to admit. Theory as an instrument of policy may be seen as belittling, or underestimating, human agency, but is that, in any sense, true, when it is human agency that designs these theories in the first place and for a specific purpose?

Economic sanctions and military sanctions are designed to put others out of business. They are a play for advantage. “Taking advantage of someone” is often considered bad behaviour. Yet businessmen take advantage of market opportunities. Social climbers take advantage of social networks. Perhaps it is an extension of human selfishness (a prominent American of Irish descent once gave the following piece of advice to the first leaders of a modern Irish state: you will have to start to learn how to become “intelligently selfish” in all your actions if you are to learn how to begin to succeed).

Laws of advantages: are they always the common bond between economies and societies? To unassuming individuals like myself, the concept seems, on a very real or personal level, quite alien and mysterious. And yet the study of history—the analyses of societies—can make it very manifest, on an intellectual level, why it is a factor governing human behaviour. Why did the Caesars never think of the immorality of enslaving all those whom they defeated in battle? Because their purpose in going to war in the first place was the same as those businesses who take over other businesses in our own day: the desire to have a larger and more profitable workforce at their disposal. All they were doing was following what they understood to be a basic law of advantage in economy and society. Terrible stuff really, but real all the same, much though my personality cannot abide by the behaviour. As an English historian once said to me with a condescending smile, “you will always be on the side of Asterix, won’t you?” Perhaps I will. The big boys play with big toys, and the rest of us will place our faith in Getafix, even if we are not blind to the relevance of Vitalstatistix. There’s a cartoonish thought to bring some balance to the day that is in it. If I could convert that thought into a tune, my day would seem complete.