I had occasion to read some New York Times newspapers from 1917 and 1918, and they were filled with stories about how Mr. Lenine's (sic) government was about to fall if not already in flight. Off the mark by 70 years or so, and Russia is still run by former CP nomenklatura.
Anywho, I've long since realized that it's all too-easy to do both sabotage, terrorism and other evil things very easily without being caught. The fact that it doesn't happen fairly regularly on a grand scale that brings society to a halt though makes we wonder if there are an appreciable amount of such evil people that are willing or incentivized to do those evil acts. A sort of "Drake equation" look at it, I guess.
Historically, biological warfare research has focused on pathogens like anthrax that have very low human-to-human transmission risk, for two reasons. One is that, if your germ-warfare bomb starts an epidemic, it barely matters which sides of the battle lines it falls on; if it thins your own ranks less than those of the enemy, it's only because your troops (and their families dying back home) are in better condition or have better sanitary measures in place. The other is that, if you can't stop the deaths when the enemy surrenders, the germ-warfare bomb doesn't give the enemy any incentive to surrender.
Evil things do happen fairly regularly on a grand scale. But doing things on a grand scale has historically required a centralized government to organize them. That's still true for a little while longer.
EDIT: and by "Russians" here I rather mean "former Soviet citizens".
https://en.wikipedia.org/wiki/Holodomor
There are many other sources / economists who will support that, wikipedia is just the fastest.
Stalin's government did do a great job of ramping up industrial production before and during WW2.
The economic landscape of the US at the time was the Depression, whereas the USSR economy was chugging along, other than the poor harvest in the Ukraine that year. Walter Duranty of the New York Times visited Ukraine at the time, and said the harvest was not a good one but a lot of reports coming out of the Ukraine were overblown.
The point is, whatever survivor's of thirties tell, thirties were a terrible time, even if they were living in a relatively well off Moscow.
That's the only truth, not that of lunatical historians which have nothing, but digits to look on, and imagining things well knowing that pretty much nothing in official economics documents from USSR' reflected reality.
Stalin, and his industrial proves is another busted for 100th time trope, straight out of original propaganda. A thing glaringly obvious to any Russian citizen who had at some time a surviving relative who went through that time, but not to people who purposefully keep returning to it for search of their worldview validation "alternative facts"
I am not sure how earlier political liberalization could have saved the USSR, which was essentially a (communist) imperialist dictatorship.
NK doesn't go to wars outside it. And they have support of China. This surely supports a long term stability... but how much of a long term, remains to be seen.