I think they mean insurgency as in resistance in occupied areas.

Yes, indeed. Can you buy or build a drone in the US? No problem. Can you get explosives or other nasty stuff to arm it? No issue for a determined group. Can you find an undefended soft target? Of course, there is a smorgasboard of those.

I think basically everyone except North Korea is. Anyone who allows goods and people to move through their borders with any level of freedom can theoretically get attacked like Russia did.

One person making a drone is far different from China staging an attack.

Then they’re commandos or special forces. ‘Insurgents’ implies an uprising against a central government, and serves to reinforce the Russian narrative of Ukraine being part of their empire.

The attack on Moscow’s strategic bomber fleet was not carried out by resistance fighters in e.g. Crimea, which would be the implication under that interpretation.

Exactly, it's a modern day trojan horse. It seems to be fairly easy to then potentially pin the attack on just about anyone using shell companies for shipment. Especially with the deregulation and removal of so many safety and security positions over the last several months.

I was reading a little about the beeper attacks the and I think even now there is still some uncertainty about which company actually worked with the Mossad to manufacture the batteries that contained the explosive.

The only reason I even bring that up, is that there were so many steps involving so many different groups of legitimate manufacturing companies as well as shell companies to ship the beepers. Some of the beepers were even taken apart and inspected before being distributed as a security measure, but they had used such a small amount of explosive fuel within the batteries, that it was completely missed.

Unless there's another beeper attack I missed, the one last September was directed at Hezbollah, across Lebanon and Syria.