In it, Morris argues that war is actually quite good for something, namely peace.
Basically the idea is that as long as the same side keeps winning all the wars they are involved in then people will eventually be too scared to fight it and we will all live long and prosper.
In other words, living under the Roman Empire was pretty grim when they were torching your village and raping your women but once all the dust had settled and the blokes had been enslaved or killed life was actually pretty good.
Morris crunched the numbers of the past 15,000 years and found that in Stone Age tribal society up to one in five people might have met a violent death. In the first century that number was reckoned to be just three or four people out of a hundred.
The same is broadly true of virtually all monolithic empires, from the Persian to the British. Once the war has been waged and won, even the most dictatorial ruler usually just wants their subjects to shut up, work hard and pay their taxes.
And of course the best way for any state to ensure that its citizens do not fight among themselves, nor rise up against the government, nor be invaded by external threats is to make sure that its capacity for force is so overwhelming that all parties know to do so would be futile. The state must have an absolute monopoly on violence.
The idea that peace can only come with some kind of subjugation or constant threat of reprisal sounds pretty scary but it is also the way the world has always been throughout all of human history. Indeed, that is the whole reason we have a police force.
Idealists have long imagined a better world and created theoretical utopias of absolute equality but virtually every time they have ever been put into practice they have descended into totalitarianism.
Likewise, progressives often complain about the state of the world today but it is only unfair or oppressive compared to an imagined ideal that has never been reached. All in all, the world is almost certainly a more peaceful, prosperous and democratic place than it has ever been.
Indeed, if we go back only a century we find humanity in the midst of the bloodiest and most clinically and industrially brutal slaughter it had ever witnessed, The Great War — the war that was supposed to be the one that ended all wars.
Many have argued that Germany gambled on the fact that Britain would not enter the war and certainly Britain was the power of whom Germany was most scared but obviously it was not scared enough.
The Kaiser must have figured that if worst came to worst Germany could possibly take Britain on. As the UK had shifted its focus from military to economic ascendancy, its reputation as a "global cop" had weakened.
In short, the British Empire was not warlike enough and so the worst war of all began. And then a generation later that led to an even bigger and bloodier war, accompanied by mass genocide on an unprecedented scale. In all, the first half of the 20th century was probably the most comprehensively murderous period of human existence on this planet. And it may all have come down to the fact that there was no single power strong enough to stop it from happening in the first place.
But what, you might ask, does this have to do with anything?
Well, the catch is that since World War II we have had an extraordinarily long period of global peace and stability. And this is because there has really only been one great superpower in the world. Even during the Cold War the US was always ascendant and since the collapse of the Soviet Union it has been almost wholly unchallenged.
It is certainly not perfect but, as global empires go, it is probably the best we've ever had. America, for all its faults, usually tries to be good — or, failing that, at least pretends to be.
World War II was concluded with the dropping of atomic bombs that levelled two cities. The two major conflicts between east and west since 1945 have been the Korean War, which ended in a ceasefire that is still being negotiated, and the Vietnam War, which was ended by peaceful protests. In World War II the penalty for desertion was death. A generation later all a draft dodger had to do was live in Canada — although many would argue this was an even worse fate.
In other words, in a world of horrible bosses, America is probably the least horrible to work for. Perhaps not compared to a Byron Bay African drumming circle but certainly compared to almost every other phase of human history.
The Americans are a bit like the captain of a high school football team. They want to be popular, win every game and decide who's cool or not. And of course they often bully the weak and weedy but they usually try not to kill them where possible.
Instead America just sits there with the most powerful military in the world and silently dares anyone to attack it or its mates, which is why we are able to negotiate trade deals with China instead of having them just drop a landing strip on us and why we were able to waltz into East Timor and liberate its gas fields — er, I mean people.
It's also why New Zealand has been able to trade in its entire defence force for a rubber dinghy and still not get invaded by Western Samoa.
But, of course, there is another catch. According to an interview Morris gave to the BBC's History Extra magazine a couple of years ago, this unprecedentedly peaceful period of US domination is likely to end somewhere in the 2040s — and that was his prediction before Donald Trump got elected. No doubt he now yearns for such heady optimism.
Morris called this prospect "really, really scary", which for a professor at Stanford University with a PhD from Cambridge is itself a pretty scary thing to say. And so we have about 22 years to get it together or we're all totally screwed.
China is on the rise, Russia is acting all bolshie again and America's power is fading while its strategic alliances weaken. Its once unbreakable Pacific ally, the Philippines, is now run by a murderous madman who has swung to Putin, there is no longer even the pretence of strategic co-operation with China and its closest allies in Europe are now off-side and looking at going it alone. Even America's best friend and next-door neighbour, Canada, is now massively pissed because of the Trumpian trade war.
The rise of China is arguably the product of organic global forces, if not just sheer arithmetic, yet it is coupled with an aggressive surge in nationalism that has seen a doggedly anti-democratic government install its leader as dictator for life, seize control of international trade routes by building new island territories from nothing and effectively wipe Taiwan off the face of the map by demanding any airline that goes there declare it part of China.
The theory was always that as China became more economically liberal it would also become more politically liberal yet in fact the opposite has happened. It has used its global market power to double down on its existing brand of weird communo-capitalism, and if anyone wants to protest about it they have to go to Hong Kong.
And they thought the same thing about the Russkis but instead they just keep getting weirder and weirder. The head of the KGB has taken over the country and his biggest problem is deciding whether to make himself prime minister or president and what constitutes a plausible landslide majority. Meanwhile his cronies are invading the Ukraine, shooting down passenger jets and poisoning double-agents in English country gardens.
Honestly, it's like Jason Bourne sharted on an early draft of Red Heat and then gave it to Michael Bay.
And while all this is going on, America's relationships are blowing up like an Irish family Christmas, which is undeniably due to whatever is or isn't happening in Donald Trump's head between the hours of two and three o'clock in the morning and whatever bar Rudy Giuliani happened to be in at the same time.
But say what you like about Trump, at least he was democratically elected. Again, even for all its faults, America tries to be legit.
And so the catch within the catch within the catch is that even with Trump's infuriatingly erratic, idiotic and morally dubious presidency, we actually need him to succeed. America really must be made great again, otherwise the world will at best be seamlessly overrun by a far more despotic and malevolent empire and at worst descend once more into global conflict, be it a trade war that decimates the international economy and plunges countless people into chaos and poverty or the actual killing kind.
This is a genuine existential threat for liberal democracy and what we have come to take for granted as "civilisation", yet the arbiters of online outrage are more concerned with the US President bonking a porn star, a kiss the Filipino president gave a woman at a press conference and calls for Theresa May to blow up both her prime ministership and what was once the United Kingdom by forcing Northern Ireland to legalise abortion using powers she doesn't actually have.
The theory was always that as China became more economically liberal it would also become more politically liberal yet in fact the opposite has happened. It has used its global market power to double down on its existing brand of weird communo-capitalism, and if anyone wants to protest about it they have to go to Hong Kong.
And they thought the same thing about the Russkis but instead they just keep getting weirder and weirder. The head of the KGB has taken over the country and his biggest problem is deciding whether to make himself prime minister or president and what constitutes a plausible landslide majority. Meanwhile his cronies are invading the Ukraine, shooting down passenger jets and poisoning double-agents in English country gardens.
Honestly, it's like Jason Bourne sharted on an early draft of Red Heat and then gave it to Michael Bay.
And while all this is going on, America's relationships are blowing up like an Irish family Christmas, which is undeniably due to whatever is or isn't happening in Donald Trump's head between the hours of two and three o'clock in the morning and whatever bar Rudy Giuliani happened to be in at the same time.
But say what you like about Trump, at least he was democratically elected. Again, even for all its faults, America tries to be legit.
And so the catch within the catch within the catch is that even with Trump's infuriatingly erratic, idiotic and morally dubious presidency, we actually need him to succeed. America really must be made great again, otherwise the world will at best be seamlessly overrun by a far more despotic and malevolent empire and at worst descend once more into global conflict, be it a trade war that decimates the international economy and plunges countless people into chaos and poverty or the actual killing kind.
This is a genuine existential threat for liberal democracy and what we have come to take for granted as "civilisation", yet the arbiters of online outrage are more concerned with the US President bonking a porn star, a kiss the Filipino president gave a woman at a press conference and calls for Theresa May to blow up both her prime ministership and what was once the United Kingdom by forcing Northern Ireland to legalise abortion using powers she doesn't actually have.