I.B. Tauris (2021) e-book 192pp  £14.39 (ISBN 9780857725066)

Is war part of human nature? It was certainly a big part of the ancient world and is still just as big today. Professor Bradford reckons that the United States has been at war somewhere for 30 of the last 70 years. In the UK 2016 was the first year for almost 50 years that no British soldier died on operations overseas.

Western military culture, its vocabulary and metaphor, derive from the ancients. Poets, playwrights, historians—all of them wrote about war and battles, courage and cowardice, slaughter and victory, strategy and tactics. Harold Macmillan carried his Greek classics into the First World War trenches; the much-decorated Colonel Chesty Puller, reading Caesar’s Gallic Wars at the battle of Guadalcanal, followed his example in fortifying his position each night.

Caesar himself looked back to the exploits of Alexander the Great; Alexander in turn looked back to the Iliad. And it is the Iliad which is the premier literary work of warfare, lost for a thousand years after the fall of Rome but rediscovered in the 14th C and still in print today. Some 27 centuries after it was composed, the Iliad compels, perhaps because it does not spare the brutality of war alongside the glory and the pathos, and because it is so beautifully balanced: though a Greek writer, he does not make either the Trojans or the Greeks the bad guys that modern readers might prefer to see. Where the gods direct human action, the results of war are arbitrary, as combat veterans like B. himself understand better than the rest of us, and do not confirm moral values.

B. takes us through the evolution of warfare from simple hand-to-hand fighting to the introduction of chariots and the cavalry, probably the biggest change until gunpowder and longer-range warships. Assyrian armies had archers, slingers, engineers, alongside cavalry and infantry. The Greek cities fielded citizen armies. The Romans modernised army organisation: 4th century reformers such as Camillus and Vegetius (De re militari) influenced later militaries right up to 18th C Austria and Napoleon.

Light cavalry, pikemen and musketeers succeeded the armoured knights. Until the arrival of gunpowder, city walls built in Roman times could be endlessly repaired and restored. Charles VIII of France needed a 40-gun siege train to conquer Italy. The battle of Ravenna (1512) saw the first exchange of artillery fire, Breitenfield (1631) the first use of manoeuvre and fast-moving firepower.

Naval warfare evolved more slowly, with ramming remaining the technique right up to the 16th C and the use of firearms and bow-mounted cannons at the battle of Lepanto (1571). It was another 250 years before the next major change—the first steam-powered battle in the Gulf of Itea in 1827, the same year that saw the last great battle of sail at Navarino.

On land at the same time armies began to multiply. Napoleon’s were the first to be bigger than an average Roman army: he deployed citizen soldiers in fast-moving attacks following up artillery fire. Over in the United States, conscripted manpower and the first use of railroads enabled generals to build numerical superiority of up to 4 to 1 before they engaged, even with maxim guns. Military mass climaxed in the two world wars, with vast armies duelling across front lines of hundreds of miles. The horrors of chemical, biological or even nuclear weapons have not reduced conventional warfare in our own time.

So why do men fight? For the ancients, after a mythical golden age, war was a constant: men fought to be able to live in peace without injustice. War was a means of seeking redress, as per the Iliad. Greek and Roman thinkers agonised over its righteousness: we owe them the theories of both a just war (ius ad bellum) and the just waging of war (ius in bello). Retaliation and self-defence were legitimate, provided war was declared and the potential enemy given the chance to make amends. Strife was seen as part of human nature, kept in check by justice.

The concept of a “just war” was therefore rooted in the laws of nature: the right to defend oneself and to acquire the means of life. In turn Frontinus, Aquinas, Machiavelli (whose Art of War is still in print), Hobbes, Grotius and John Stuart Mill wrestled with the realities: how should preventative war be justified? What were the rights of civilians caught up in sieges and battles? What exactly was the right to imperialist conquest? Codifying the laws of war did not prevent the mass bombing in the last century of civilians in London, Germany or Japan. Cicero was prescient: silent enim leges inter arma.

Today there is stronger international law: force must be necessary and proportionate, and restricted to deal with an immediate threat. Non-combatants’ rights must be respected. In the recent coalition campaign against the Daesh in Iraq and Syria (2014-18), the commander of each national air component, including the RAF, had a legal adviser beside his desk to consult before every strike. Even so the war against terror is constrained by the concept of immediacy which becomes rather meaningless when the terrorist can strike or bomb without warning.

The ancient writers, especially the historians, saw it all at first hand (Thucydides and Tacitus were generals too): war was brutal but nonetheless a common experience. Today we delegate it—to professional forces, to long-distance weapons, even to private and undeclared militaries. But we cannot avoid the huge moral issues involved. B. introduces these for us, and points the reader wanting more towards Michael Walzer’s Just and Unjust Wars (1977). I would also recommend Margaret MacMillan’s War (2020) based on her insightful Reith Lectures ‘The Mark of Cain’.

Sir Michael Fallon is a former Defence Secretary