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.

From whom?

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.

Gestures Broadly

The Billion Dollar Question.

Japan tried to bomb the US by sending balloons over the jet stream and it was largely ineffective due to the range and lack of precision. Moving a weapon across an ocean and into range of a target without a ton of telecommunication support and manual intervention would be a herculean task. Far easier to just bomb one of the hundreds of US military bases local to your neighborhood, as with the Al Qaeda bombing of the US base in Somalia or the Houthis in Yemen targeting US bases and large ships trying to navigate the Red Sea.

But domestically? A little surprised nobody has tried to turn a large drone aircraft into a weapon for an Oklahoma City style attack.

If you look at the techniques employed by the Ukrainian insurgents against Russia, explosives embedded into the shipping containers of large trucks have been incredibly potent. Drones hidden within the tops of shipping containers put Ukraine within striking distance of the Russian bomber fleet.

Definitely something a committed insurgency within the States could employ against police/military.

Ukrainian insurgents defenders

Drones have an incredibly limited range, so any drone attack would have to originate either inside the United States, off our coasts, or within the borders of Canada and Mexico.

And? What's stopping those scenarios from happening?

NK has a bunch of manufacturing plants. Lots of trucks and trains cross their borders with Russia, China, and even South Korea every day.

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

When they're behind enemy lines, I'd say they're on offense.

Highly unlikely.

Just look at the list of countries that the USA has pissed off in the last whatever years, and choose one at random.

Its possible a sleeper cell of terrorists could effectuate some small area drone strikes with commercial off the shelf drones and improvised explosives.

The large scale military drones you are envisioning that can do the same damage as military aerial bombardment, that is a much harder thing to "sneak" into the US at any kind of scale or to build in secret.

As for future state actor capabilities. It seems possible that China is working on drone tech deployed from submarines or other force-projection platforms. Yet another reason to avoid a hot war with near peer militaries in current year.

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.

Ok I'll just come out and say this, I think it would be easy for a certain corrupt individual to create a false flag drone attack from a "foreign adversary" in order to boost patriotic morale and gain the support necessary to drag a certain country into a war he has repeatedly and very publicly announced he does not want to be involved in despite all evidence to the contrary.

Especially given that corrupt individual has dismantled several safety measures and regulations and eliminated positions of individuals who are trained to keep something like this from happening.

If you look at the amount of damage done by the Beeper attacks a few years ago, you really don't need a gigantic war drone to cause a catastrophe in certain conditions.

I know it sounds paranoid AF, but I find it especially odd that same individual is trying to shut down the only agency that would thoroughly investigate an industrial chemical explosion if one were to occur.
https://grist.org/energy/trump-quietly-shutters-the-only-federal-agency-that-investigates-industrial-chemical-explosions/

Specifically? Who knows, but the concept has already been tested by someone , and afaik, they have still not figured out who did it.

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.