French SF novel: isolationist Europe, mimicking insects

Question

Bit of a long shot this.

In the mid-90s I lived in France for a bit and read a particular SF novel which has stuck in my mind. It was a near-future scenario where Europe had become extremely isolationist, to the point that outsiders were not allowed in at all; there was an impassable barrier around the border and automatic (DNA?) scanners everywhere inside.

The protagonist was an agent for Britain, which was outside the barrier; he finds a way to sneak into Europe and (he believes) fool the scanners, although this turns out not to work fully.

Other things I remember:

• there was some kind of space-stretching technology which was used to make living in tiny apartments more bearable;
• at some point the agent gets taken to a prison camp where he encounters a scientist who has been training some microscopic insects to mimic objects at the molecular level; the insects copy the agent's son, and he prefers the copy to the original;
• at the end the space-stretching thing goes wrong in some way which affects all of Europe, leaving one character as somehow the "god" of the whole area.

It was a very weird book, and I think my copy was missing the last few pages, so I never learned how it ended.

Answer 1

This is almost certainly Cette chère humanité by Philippe Curval (1976, translated in 1981 as Brave Old World). It is a part of the book series L'Europe après la pluie.

Automated translation of the summary from the wikipedia article in French:

For the past twenty years, Marcom, once the Europe of the Common Market, has been cut off from the rest of the world and withdrawn behind high walls bristling with impenetrable defenses.

However, a cry for help has managed to penetrate the wall, informing the rest of the planet that a formidable danger threatens it.

The story also features slowing-time devices in people's apartments; and one of the characters is composed of tiny insects capable of taking any form.

If you want more details about the story, it's difficult to find online reviews about it in English - I just found this one:

In the late 21st century, Marcom (a high-tech, 13-state Common Market), hiding itself behind impenetrable energy barriers, has become an utterly rigid, self-absorbed, nostalgia-sodden police state: it's secretly controlled by the Slow Time Company, which markets devices that stretch time (thus providing longevity) and space [...]

[...] when the outside world discovers that Marcom's spacetime warps are threatening to drop the entire Earth out of its continuum, attorney Belgacen Attia is sent to penetrate Marcom's deadly neurological barriers and destroy the slow time network.

Otherwise, you'll mostly find resources in French about it, like this short review or this academic analysis of the novel, which mentions the mimicking insects (automated translation):

Glycine, a telepathic simulacrum of a young woman made up of tiny insects capable of giving her every conceivable shape, probes Sahel's unconscious to find a memory left there by his father.

This other review in French gives more details about the mimicking insects and the Glycine character (again, automated translation):

Glycine is a collective intelligence created by artist and scientist Ferenczi, taking the form of a young girl composed of a gigantic swarm of "pulvis mutabilis", microscopic insects capable of imitating any life form whose intelligence and body appear more powerful than that of a human. She thus surpasses the life form she is supposed to imitate thanks to the multitude of individuals that make up her, which may make her a posthuman, since her humanity is called into question by the characters, but also by her abilities, which surpass standard humanity.