Ian McEwan could best be described as a realist novelist, in addition to other descriptions that could best suit specific novels. For instance, Atonement is somewhat a metafiction where Briony was writing, partly, her story, in addition to being a historical novel. On Chesil Beach is also, somewhat, a historical novel, which, through its characters, provides the pointers of change that has taken place.
Saturday (2005; 291 - Anchor Books) by Ian McEwan is the ultimate realist novel one might read and it is also one that would raise a lot of questions. The story is set on a specific date, February 13, 2003 - the day thousands (if not millions) marched against America's invasion of Iraq following the 9-11 terrorist attack. This attack means that terrorism has become a major topic for discussion including the Perowne household. The Perownes have a peaceful home. Their Blues guitarist son Theo, though has dropped out of school, was far from delinquent and very focused in his career. Their daughter Daisy, who took after Henry's father-in-law - John Grammaticus, was an almost-published poet. Henry is a neurosurgeon and Rosalind was a lawyer. On the day that the story is set, there was to be a family reunion to tidy relations between Daisy and John.
This was the peace of the household until, on the day of the demonstration, Perowne encountered a minor traffic accident with a gang of three but managed to extricate himself from further the physical abuse, after refusing to honour the cash payment demanded by the group. Henry capitalised on Baxter's, the leader, neurological problem. However, Baxter and Nigel would surreptitiously follow Perowne home when the family has gathered and would hold them at knife-point and would begin to toy with them.
Through the story, McEwan discussed the conundrum of good and evil, using the 9-11 attack and the impending invasion of America as the motif. For instance, according to Perowne, Saddam is evil and has done evil things against his people and would need to be removed. However, Perowne was neither pro-war nor anti-war. For him, Saddam must go. He took on this behaviour because of what one of his patients - an Iraqi - had told him, which forced him to read more about Saddam. In an argument with his Daisy, he says that all those who are anti-war are pro-Saddam. The dichotomy of the choice, that you can only be one of two things smacks of George Bush's statement prior to the launch of the Iraqi invasion. In fact, according to Henry, why should one take the negative consequences of war? What about the positives? He argued that the anti-war arguments are speculations about the future and there was no need to feel certainty about it.
But this is all speculation about the future. Why should I feel any certainty about it? How about a short war, the UN doesn't fall apart, no famine, no refugees or invasions by neighbours, no flattened Baghdad and fewer deaths than Saddam causes his own people in an average year? What if the Americans try to organise a democracy, pump in the billions and leave because the President wants to get himself re-elected next year? I think you'd be still against it, and you haven't told me why? 
He added, when challenged by Daisy that he loved war, that
No rational person is for war. But in five years we might not regret it. I'd love to see the end of Saddam. You're right, it could be a disaster. But it could be the end of a disaster and the beginning of something better.
As a record of historical events, I wish that Perowne (or McEwan) was right in this instance for any casual observer would realise that he was dead wrong. The war has lasted for more than five years; people are still dying as a consequence of the war; America couldn't pulled out; Saddam was toppled but no democracy has been put in place; people die more than what Saddam was accused of; Baghdad was toppled, and it has become a haven for Al-Qaeda; and ultimately, what Saddam was accused of was never found. Perowne, regardless of his education, was your usual guy who considers his culture above all else. He hates the Chinese for their numbers and the expansion of their economy; he hates the Arabs for making their wives wear burkhas whilst the men wear suits with Rolex watches.
The effect of bombings on the general psyche of the people was also discussed briefly. When a troubled plane forced-landed at Heathrow, both Henry and Theo thought it was a failed Jihadist attack on London. In fact, the authorities thought same until it was discovered that they were not Chechnya Muslims as was suspected and that there was no Koran in the cockpit; but rather they were Christians who care not about religion. It was only when further checks were conducted on them that they were released and allowed to go. Thus, the religious sentiments were also discussed in a non ideological manner; the way the ordinary family would have discussed such matters. No moralising.
The above also relates to media coverage. It was clear that when the media realised that the plane was a distressed plane and that the pilots were not Muslims or terrorists, the news died down suddenly and was relegated to the tail-end of the news.
Another thread one could pick is the issue of moral responsibilities. Should we separate our emotions from the work we do? When Baxter fell and injured himself in the Perownes' home, it was Henry who was again called to conduct the emergency surgery to save his life. Could this not be described as conflict of interest situation? Would not Henry have been accused if Baxter had died in surgery? These are necessary questions which need to be answered in this situation. Was Perowne morally stronger because Baxter lived? Or because he knew that Baxter was a hopeless case.
Baxter was afflicted with the Huntington's Disease, which is a "neurodegenerative genetic disorder that affects muscle coordination and leads to cognitive decline and psychiatric problems" caused by the repetition of the 3-letter genetic codon CAG. This softened Perowne towards Baxter's aggressive behaviour, knowing that he had little time left before he is completely incarcerated in a psychiatric institution. The novel is heavy on issues of neurology and poetry. And it is said that McEwan observed the neurosurgeon - Neil Kitchen - at work for the two years he took to write this novel.
Regardless of the above, of all the four novels I have read by McEwan, this would rank low; not because of it is steeped in realism but because the story-line is a bit lethargic. Nothing seems to be happening until the 213th page, when the incident occurred. Yet, this incident - the minor traffic accident, which was meant to carry the story, passed almost smoothly until its repercussions were felt towards the end. McEwan could have written about anything for the entire hundreds of pages. It would take perseverance for a reader not to give up after 100 pages. The use of technical jargon was excessive, especially regarding the neurosurgery; he however showed the extent of research that went into it.
I cannot say I am recommending it or not; but if you are a McEwan fan, you might like it. If you have never read any of his books, I believe this is not the starting point for you.