I just read of the explosive assassination of a senior Russian general outside his Moscow-area home. Ukraine claims the responsibility for it. The claim seems likely.
This gets me to thinking of how tough an opponent Russia voluntarily took on. Ukraine is literally nextdoor and many of its citizens are native Russian speakers. The analogy would be if the US attacked Canada.
On a nearly month-long cruise to Australia that ended coincidentally a month ago, our tablemates at supper were a family of four very nice Canadians. I never once heard “eh?” pronounced “long a with a rising inflection” nor “about” pronounced “aboot.” In other words their speech patterns didn’t give away their nationality at all.
That they had relatives living in the States was nearly a given. With forged or stolen documents they could pass as residents of Ohio or Michigan or Minnesota and totally get away with the subterfuge.
My point: There are obviously thousands of Ukrainians who could pass for Russians beyond the ability of any passerby or tablemate to detect. Go to war against such similar folk, and find out their ability to infiltrate your land and do you harm is nearly infinite.
Obviously, Ukraine is doing some of this, and could do much more of it. It would create mass paranoia far beyond the Russian historical norm of chronic, low grade paranoia. Be glad we get along with the Canadians.