Many bad inventions have come from my home country Italy, from the plague
of the 14th century to the mafia, from
Mussolini (the prototype for all the authoritarian leaders and demagogues of
the 20th century) to Berlusconi (the prototype for Donald Trump).
Armitage noted another one: civil war. He dates the origins of civil war
to the Roman Republic. War is defined as a violent conflict by a country
against an enemy country.
Civil war is a war that doesn't have an enemy country. Civil war has become the preferred kind of war of the post-Cold War age. Until 1991 most armed conflicts in the world were conflicts between armies of different countries, like the Arab-Israeli conflict or the Indian-Pakistani conflict. After 1991 one can say that only the USA has engaged in that kind of conflict: two wars against Iraq and one against Afghanistan. The rest of warfare has been civil wars. Armitage also notes that civil wars tend to last longer than wars between states, and kill more people (the Civil War of the USA killed 750,000 people out of a population of 31 million). The civil wars of our age take place in the poor countries of the world. The rich world (Europe and North America) has been immune. The poor countries have become much poorer, from Libya to Syria, from Afghanistan to Sudan.
Armitage discusses the definition of "civil war". There's a point in time in which the internal war becomes a "revolution", not a "civil war". "Civil war" sounds negative and destructive, "revolution" sounds positive and constructive. We have scientific revolutions, not scientific civil wars. The change took place during the French civil war that now everybody calls "French Revolution". The Russian civil war of 1917 is routinely called "Russian Revolution". Instead the civil war of the USA in 1861-65 is never called a revolution, although it led to the abolition of slavery, a revolutionary concept.
Surprisingly, Armitage never notices the ideological bias in calling a war "revolution". The Russian conflict of 1917 is called "Russian revolution" and the conflict in China between Mao and Chiang Kaishek, that ended in 1949, is called the "Chinese revolution", whereas the Spanish conflict of 1936 between Franco and the Marxists is called "Spanish civil war", not Spanish revolution, as if to deny Franco the merits that leftists attribute to Mao and Lenin. Hence it looks like in the 20th century leftists decided which conflicts deserved the name "revolution" based on whether the result was a Marxist-Leninist dictatorship. The various rebellions that ousted the communist regimes of Eastern Union after the implosion of the Soviet Union in 1989 are not called "revolutions" although they very much resemble the Russian revolution of 1917: the difference is that the sides were reversed, with the Marxist-Leninist dictatorship being ousted.
There are different kinds of civil wars. Most of the famous civil wars of Rome and of the civil wars of Europe were "successionist": they were about how has to succeed the dead king/emperor. The US revolution was a civil war of the secessionist kind. It was a civil war because the "Americans" themselves were divided over the independence struggle: some were loyalists and some patriots. About 60,000 loyalists eventually fled the "revolution". The Dutch revolt of the 1580s too was a secessionist civil war, as was much later the Yugoslavian civil war of the 1990s. The "French Revolution" was neither secessionist nor successionist.
Armitage's hidden ambition is not to write the great book of civil wars, the equivalent of Carl von Clausewitz's "On War" and of Hannah Arendt's "On Revolution": Armitage does little to illustrate the history of civil wars, the causes of civil wars, the evolution of civil warfare. We learn little or nothing of the difference between the Roman civil wars (whose armies were mainly mercenaries) and the civil wars of the 20th centuries (whose armies were mainly mobs of ordinary people). Reading the book, one may never realize that almost all the civil wars after the end of the Cold War happened in Islamic countries, which may or may not be a coincidence. Between World War I and the end of the Cold War, instead, there were civil wars mostly in non-Islamic countries (Spain, Peru, Nicaragua, Sri Lanka, Guatemala, Yugoslavia).
This book is mostly a cultural history of how "civil war" has been interpreted over the centuries, starting with Emer de Vattel's "The Law of Nations" (1758). Lincoln was convinced that he was not fighting a civil war but a war against a "rebellion". Francis Lieber, who wrote "General Orders No 100" (1863), the blueprint for the Geneva and Hague conventions, agreed with Lincoln. Only in 1907 the US Congress finally decided that the 1861 war had been a "civil war". Voltaire realized a big problem in deciding when a conflict can be considered a civil war: it all depends on what you consider as the "place" at war. He considered Europe as one big nation in his world history titled "Essay on the Customs and the Spirit of the Nations" (1756) and therefore to him all European wars were civil wars: wars between Europeans inside Europe. Francois Fenelon, in his book "Dialogues of the Dead" (1712), had gone as far as to argue that all wars are civil wars because they are wars between human beings, and humankind can be viewed as one giant nation. On the other hand, John Rawls used a microscopic (not macroscopic) lens and recognized nine different kinds of warfare, only one of which qualifies as "civil war", basically only the French revolution. The others are wars of secession like the Civil War of the USA, wars of colonial liberation like the Algerian war and the Independence War of the USA, wars of intervention to protect human rights, wars of unification (like Garibaldi's war in Italy and the War of the Roses in England), guerrilla wars (like the Vietnam war), plus ordinary wars between states, wars of conquest and religious crusades. In 1973 Michel Foucault lectured on civil war showing that it is the ordinary state of things: "politics is the continuation of civil war".
One also wonders if today we are not inventing a new kind of civil war, a cold "civil war" that mostly happens in the media, and increasingly on the social media of the Internet. In the USA the animosity between Democrats and Republicans is dangerously close to becoming violent.