Lev Davidovich Trotsky's trajectory through history was set by two competing personality traits: his ability to be enormously persuasive and his tendency to be spectacularly wrong. Without polemical skill, exercised through newspaper articles and rabble-rousing orations, he would never have requisitioned the Russian state for international Marxist revolution. But if he been right about the world's readiness for that revolution in 1917, we would all now be living in a socialist global republic. Robert Service, meanwhile, would be in the gulag for having written a non-hagiographic biography of the Bolshevik agitator-in-chief.

Service is never unkind to his subject, but nor is he an acolyte. One of the great functions his book performs, aside from being a compelling read, is to flesh out a non-Trotskyite version of Trotsky. That person comes across as a prodigious force in any milieu he entered, but not an especially endearing one. Trotsky acquired a revolutionary fervour in his late teens and honed it into a radical political agenda by verbally jousting with everyone he came across. He was not incapable of changing his mind, but he was certainly reluctant, and he bowed only to immovable historical forces. He was persuaded to sign a peace treaty with imperial Germany, for example, because he had seen at first hand the appalling state of Russia's military defences. Facts on the ground could shift him. Other people's arguments seem to have caused him only irritation.

Natural belligerence served Trotsky well in pre-1917 radical left politics, and as a military commander in the civil war. But it was his undoing in peacetime government. He was, by all accounts, a mesmerising rhetorical performer and a courageous fighter. He must have had personal charisma. But he lacked the soft skills required to sway committees and shore up alliances in party politics. That, more than any doctrinal schism, is why he was outmanoeuvred by Stalin. Trotsky was certainly less prolific a murderer than his arch rival, but he was brutal nonetheless. Summary execution was his preferred method of military discipline.

There is no moralism in Robert Service's narrative  and there is no need. It is plain from the facts that Trotsky was a quite brilliant historical phenomenon; and not a very nice man.