Image 1991 In Kurdistan during the Persian Gulf war. Credit... From “Hitch-22”

Even when he was a young man, Hitchens’s bête noire was Stalin. Born in 1949, the author came of age during that heady moment of “revolution within the revolution,” that time when Trotskyism had captured the imaginations of an international class of students, intellectuals and organizers. He was a natural soixante-huitard, a Labour Party member and anti-Vietnam War demonstrator in advance of 1968 itself, and one can feel his enthusiasm for that era still. “If you have never yourself had the experience of feeling that you are yoked to the great steam engine of his­tory,” he says, “then allow me to inform you that the conviction is a very intoxicating one.”

Image 2004 With Ian McEwan, left, and Martin Amis in Uruguay. Credit... From “Hitch-22”

As soon as we leave Oxford, however, and follow him on his tour through the revolutionist’s Fodor’s (he goes to Havana and Prague, Poland and Portugal), we begin to hear about the ways that international socialism isn’t quite delivering on its promise, either from his young perspective or from the perspective of disillusioned comrades he meets along the way. We also follow Hitchens to the Iraq of 1976, which he now more or less admits to have gotten wrong — “I should have registered the way that people almost automatically flinched at the mention of the name Sad­dam Hussein” — and we follow him back there after Desert Storm, when he very much wished to get it right. And there’s a whole chapter about Salman Rushdie, whose involuntary fugitive status occasions a moment in 1989 when the personal and the political truly do inter­twine, with Hitchens looking aghast at those on the left who, under the guise of multi­cultural ­sensitivity, were unwilling to condemn the ayatollah’s fatwa.

By the time 9/11 comes along, we are hardly surprised to hear the author describe its barbarism as “fascism with an Islamic face” — a phrase he coined back then that has since evolved into the blunter, catchall term “Islamo­fascism.” Little by little, he has been setting us up for his divorce from the left, and his surrender to the conviction that “the only historical revolution with any verve left in it, or any example to offer others, was the American one.” Some will find his version of events sympathetic; others will find it a cliché, the inevitable rightward drift of an old Trotskyist; and still others will violently quarrel with his tangents and disquisitions, as Hitchens so often makes one do (he may be smarter than most of us, but when he’s hellbent on making a point, he’ll haul out straw men one would just as soon leave to the cows). Personally, I didn’t lose all patience with him until the end, when he claims that although he wanted the “moral arithmetic” to add up so that he could remain on “the ‘left’ side of the column,” he couldn’t when it came to Bosnia: “I was brought to the abrupt admission that, if the majority of my former friends got their way about non­intervention, there would be another genocide on European soil.” Perhaps this was true of the intellectual left, but it was Bill Clinton, a center-left president Hitchens detested for his opportunism and slipperiness, who finally ordered the troops in, and he did so over a squall of conservative objection, with 29 Republican senators voting against the intervention, versus only one Democrat. (How’s that arithmetic?)

The truth is, by Hitchens’s standards, his examination of how he and the left parted company is surprisingly un­strident and nonpolemical. It is, in fact, almost melancholic. He’s not claiming with his typical adamantine force that the balance sheets work out. And perhaps the strongest theme in “Hitch-22” is just this — that sometimes the balance sheets are an unholy mess. From the time he was young, Hitchens says, he’s tried to keep dueling notions in intellectual and emotional equipoise. His need to manage contradictions came early, with an exotic spirit for a mother and an embittered Tory for a dad. By the time he got to Oxford, he was quite accustomed to “keeping two sets of books,” passing out leaflets at car plants by day and racing off in fancier dress to the Gridiron Club by night. When he began his work at The New Statesman, he realized that “journalism was the ideal profession for someone like myself who was drawn to the Janus-faced mode of life,” in that one had to seduce both sides to hear the whole story.

So yes, Christopher Hitchens may long to be a cogent man of reason, and he can certainly be a pitiless adversary. But he knows there are two sides to any decent match, and it’s touching, in “Hitch-22,” to see how often he’ll race to the other side of the court to return his own serve. Which may explain why, though he tries to be difficult, he’s so hard to dislike.