It proves that not all sustained incompetence is malice.
But you need to prove a stronger claim: That sustained incompetence, by an actor capable of competence, and who would gain from incompetence, is not malice. But this is a case that can only be resolved in specific contexts, not in general. Because of course it's possible all the incompetence was accidental. Likewise it's possible the incompetence is being used as cover. However, it's reasonable to be suspicious in these cases.
QED.
However, for the purposes of debate lets say we strictly limit our discussion to the cases in which there is malice. We're now in a competitive context in which our upside is going to be minimized. A lot of people don't seem to realize that the prisoner dillema is actually a condemnation of rational behavior, since it traps us in the worst possible world. It's actually smarter in plenty of real world scenarios to intentionally cooperate, sacrificing your own utility, rather than engaging in tit for tat. Flowing out from this mathematical idea are many teachings in religion from the Lord Jesus Christ like being good to those who are evil to you. You can see the underlying principle in our biology too. We aren't strictly rational, we instead have emotions. In particular people who are angry with other people have health consequences. There is a biological punishment to choosing not to cooperate built into us. This shows that evolution has selected for that quality which implies there is a benefit to this. I say all this because not attributing to malice what is better explained by stupidity isn't a completely foolish idea even in the case that they actually were malicious. The world in which they merely pretended to be incompetent is less severe than the nuclear war of tit for tat that wipes out all life on Earth and leaves it an irradiated wasteland.
Regardless, this case with Russia is like your very technologically advanced friend who is destroying your art project with his reckless movement of his project around the shop. Its not cool, because if you have the ability to build a hyper-ballistic missile, you have the ability to predict the debris scatter.
So what do we do with apparently malicious governments?
Also, as a minor point: I said the true statement that sustained incompetence is not the same thing as malice. You quoted me giving examples of sustained incompetence being met with judgement. However, you asked me about situations pertaining to apparent malice rather than sustained incompetence. The situations you quoted aren't alike to the situation you asked about.
Even if they were alike they have no bearing on my claim that sustained incompetence is not equal to malice. Equality doesn't exist when there is a union. Equality exists when there is no disjoint.
There is one potentially valid interpretation of your question: instead of what do we do you could mean what ought we to do with apparently malicious governments. I admit I'm not an expert on this topic. You would be better off asking people who have studied political science, especially in the context of warfare wherein malice is more common.