I'm a Martin Amis fan. There, I said it. Ordinarily, when people ask me who my favourite contemporary novelists are, I usually slip Amis in – but almost always add that "he's a guilty pleasure" or some such similar wiggly qualification. I'm still not sure why this is necessary. Amis, most will agree, is at or near the top of the rank of best/most important living English novelists. Moreover, he's extremely erudite and a stunning prose stylist and one of those literary magicians who can do most anything. And, in fact, has undertaken to do almost everything – a police procedural, a time travel book (in that it takes place backwards in time) (about the Holocaust), memoirs, Soviet history – all in addition to those Martin Amis books (Money, Dead Babies, Yellow Dog, and most especially his high-water mark, London Fields) that are unmistakably "Martin Amis books". He's very, very good. There's just something, well, I don't know, yellow, and not-all-that-nice, and too puerilely cynical to be entirely serious about his writing. Or for us to be allowed to take it entirely seriously.

But now Amis has taken up an undeniably, unvaryingly serious subject – 9/11 and Islamist terrorism – but of course he's taken it up in an undeniably Martin Amis way. For many years, Amis was known as l'enfant terrible of British letters. Now he's into his fifties, so the crown surely needs to have passed (isn't Will Self also on the wrong side of 40 now?). But there is still an ageless and unmistakable barb to his nib.

I confess I'm generally wary of novelists taking on politics. It was with this trepidation that I picked up The Second Plane – Amis's collection of reviews, essays, and short stories related to 9/11 and the world it spawned. However, what I've now realised is that his themes here really aren't to do with politics – they are to do with death, and nihilism, and bad ideas, and good intentions, and new worlds, and messianism, and masculinity. And all these are themes that a good novelist should – and certainly this novelist does – know something about.

According to Amis, the post-9/11 era started with the appearance of the second plane, United Flight 175. Moving at over 600mph – a speed that type of jet was not meant to achieve, much less maintain – arcing in at the south tower, looking "eagerly alive, and galvanised with malice, and wholly alien", it alerted us all instantly that something much, much worse than merely the worst aviation disaster of all time was happening. "For those thousands in the South Tower, the second plane meant the end of everything. For us, its glint was the worldflash of a coming future."

In a preface, Amis admits that he got some things wrong – and, as a number of reviewers have already noted, his outlook and his politics change over the course of these pieces. (Not, most critics hasten to stress, for the better.) For instance, in the opening piece, which appeared in The Guardian a mere seven days later, he cops to succumbing to what Paul Berman, in Terror and Liberalism, called "rationalist naivete". This is the hard-to-shake worldview of rational people that the acts of others – however horrific and incomprehensible – must have some rational basis. I was pleased to dust my copy of Berman off the shelf, and review his starkest example of this: the second Palestinian Intifadah. Berman notes that the further the Palestinians descended into barbarism and depravity, the more and worse their suicide mass-murdering, the more the world got on their side. For the world had no psychologically sound alternative but to conclude that the suicide bombing was the measure of how bad Israeli oppression of the Palestinians must be. Rational themselves, most people assumed the bombing had to be a rational response to an intolerable occupation. It's simply too jarring, and too scary, and too painful to countenance the possibility of a mass pathology – a death cult – on that scale.

So, similarly, the reaction of most of the world, and Amis himself at first, to 9/11, was to ask what we had done to provoke this. He moved beyond this view, but I'll forgo a recounting of that intellectual journey, confining myself only to a few comments on a few of the pieces.

The two short stories, to me, were perhaps the least interesting. In one, he imagines the last hours of Mohammed Atta – whom most reviewers hastened to underscore was terminally constipated, not having had a bowel movement since May. This is striking and comic – but much less interesting than Amis' imagining that Atta did not relish the prospect of the killing, and was not motivated by religious motives and, finally, in the last instant was confronted with how horribly he had miscalculated the value of his own life: "Yes, how gravely he had underestimated it. How gravely he had underestimated life. His own he had hated, and had wished away; but see how long it was taking to absent itself – and with what helpless grief was he watching it go, imperturbable in its beauty and its power. Even as his flesh fried and his blood boiled, there was life, kissing its fingertips." Belying the widespread criticism of Amis as a born-again, post-9/11 right-wing nutjob, this is actually beautiful, balanced, very human stuff.

Speaking of the criticism, Amis relates how he came back to the UK in the summer of 2006, after two and a half years living in South America. He appeared on the BBC's Question Time – and got a pointed instruction in how the political ground can move right out from under you. He was asked about progress in "the Long War", and gave an answer that he thought was "almost tediously centrist". He said that, instead of invading Iraq, we should have been constructing a democratic and pluralistic Afghanistan, and hunting down al Qaeda ruthlessly in Pakistan. He was immediately confronted by a woman "near-tearful with passionate self-righteousness", who said that it was the Americans who had armed the Islamists in Afghanistan and therefore in response to 9/11, the U.S. should be bombing . . . itself. This suggestion was greeted with unanimous applause. With this, Amis realised he had basically stood in place on the political spectrum, while the left had somehow exited . . . stage left. This dislocation and disenfranchisement he shares perfectly with Christopher Hitchens, whose great friend he (incidentally?) is.

In other pieces, it must be mentioned, Amis piles onto the clownish cowboyishness of George Bush, and paints the Iraq War as an unmitigated disaster – the worst result of 9/11, in fact. (In refuting the blame-America-Firsters he says that September 2001 wasn't a self-inflicted wound, but March 2003 certainly was.) In a long and trenchant essay, he puts together his grand unified theory of "the age of horror-ism", as powered by radical Islamism, and in entirely non-punch-pulling terms: "Suicide-mass murder is more than terrorism: it is horrorism. It is a maximum malevolence. For the suicide-mass murderer asks his prospective victims to contemplate their fellow human being with a completely new order of execration." It's also very funny (in a horrifying way): "Suicide-mass murderers," Amis suggests, may just be "searching for the simplest means of getting a girlfriend. It may be, too, that some of them are searching for the simplest means of getting a drink. Although alcohol, like extramarital sex, may be strictly forbidden in life, there is, in death, no shortage of either." The whole piece can be read in the Observer here, and is very strongly recommended – even if you don't read his whole book, which you can buy on Amazon.com or Amazon.co.uk, and is also very strongly recommended.

There are several reviews here – including of Mark Steyn's controversial book America Alone, Ed Husain's The Islamist and, most unforgettably, of Paul Greengrass's documentary-style film United 93 (which, it will be readily admitted by this commentator, I sat in the cinema and sobbed out loud like a heartbroken infant for about the last half hour). This piece is called "What Will Survive of Us" – and in describing the passengers' last calls to their families, and in imagining what they might have said to their children with them on the plane, it suggests, "Love is an abstract noun, something nebulous. And yet love turns out to be the only part of us that is solid, as the whole world turns upside down and the screen goes black. We can't tell if it will survive us. But we can be sure that it's the last thing to go."