The precise year in which it is set is vague, and an interview with MacLeod suggests this is deliberate. It is supposed to be far enough in the future that America has become the cheap manufacturer of the world thanks to workers in indentured labour camps, with India and parts of China taking the place of the US as the place where the innovations happen and the design and programming is done. However, it is supposed to be close enough to the present day that the communications technology (phones, computers, net, TV) and media landscape are more or less the same as today - there is some hint that TV on phones is available and works and there is one mention of IP6, but they're the only suggestions that the media-tech landscape is any different from today. The general impression is that it is about 10 years ahead which is too short for the former and too long for the latter.
There are other hints that the world is different - some mention of climate change, and Britain has the Euro (but there is no hint that Britain's view of Europe is any different from the present day). Is it an independent Scotland. Possibly, probably not. It is all rather vague. The precise nature of the US, UK (or Scots and English) and French governments are not mentioned. I suspect Ken thinks this doesn't matter.
Now, you may say, it is just a prejudice on your part Mr. Weasel that the author should not elide these matters. To an extent you are possibly right, there are plenty of novels that could be written with this sort of vague background, but not what is obviously supposed to be an edgy techno-thriller.
There are things that don't make sense... The eponymous Execution Channel (and if you don't want to know what it is, look away now), is a channel showing rolling executions. It is, wait for it, controlled by a Chinese AI which sucks the pictures off surveillance cameras via back-doors in them, uses its AI'y goodness to recognise executions, and puts them on its channel. There is no adequate motivation for the computer networking landscape having changed so much that such a back-door is remotely plausible, and the Execution Channel is only tangentially relevant to the plot.
There is a great detail of tedious spy novel stylee tradecraft. Yada yada mail-drop yada yada codeword yada yada false trail yada yada. You know the sort of thing, and it has never seemed so tedious to me.
The main plot concerns a nuclear blast (or is it something new, exciting and SF-nal, and if so, does anything that Ken writes make us care?), and a subsequent terror campaign in Britain. The main protagonist works out who it is. He does this, and I kid you not, by doing lots of web surfing, looking at databases he has back doors in, and puts this all in a spreadsheet. At the end he meets with some other characters and tells us who it is. BUT we don't get to see any of his working. Show your working, exams say. But our protagonist and Mr MacLeod don't do this. There are no clues we can spot, or not, nothing about what the protagonist has found, only that he HAS found something.
So, of course, when he tells the other characters we don't care. Partly because we weren't remotely involved in the process, and partly because the world of the book is so vague there is no reason for us to care who it was. In fact, I forget. But there is no reason I should remember, because nothing really hinges on it.
The denoument, which I am not going to spoil, is just bizarre. Maybe it is supposed to be symbolic (but of what?) or is supposed to be a bizarre post-modern joke. I am baffled.