https://en.wikipedia.org/wiki/Les_Soul%C3%A8vements_de_la_Te...
Even the political group "Les verts" is quite radical in their language. And those groups like "Les Soulèvements de la Terre" want a violent green revolution.
https://www.leparisien.fr/societe/les-soulevements-de-la-ter...
And most of all, why would they attack high speed rail infrastructure which is one of the greenest ways of transportation?
No, it wouldn't make any sense for an "eco-terrorist" group to do it in this way. Same as it doesn't make sense for an Islamic terrorist group.
This has Russia written all over it, from the methods to the Russians already arrested to the fool bragging about it yesterday in Bulgaria.
Because they announced it:
https://www.leparisien.fr/faits-divers/la-flamme-olympique-d...
https://www.leparisien.fr/societe/les-soulevements-de-la-ter...
on a more serious note, even if train is low-carbon, this could be seen as an anti-olympics protest which ecologists claim is an ecological disaster.
There are no similarly held opposition to trains/mass transit. Indeed, as the parent indicates, trains appear to have unanimous support from green factions.
Russia has 1 very clear long term goal, from way before they invaded Ukraine in 2014 - making Europe as weak as possible, while extracting as much money as possible. With this optic, their approach is methodical and steady, and its up to us to decide how to react. Germany's Scholz (and Merkel before, god she really did tons of damage across whole EU security wise) took the bait quite some time ago.