Ask Lemmygrad

Blackshirts and Reds by Parenti goes over some of this, IIRC (successes and failures of the USSR). I think we should be careful of taking away lessons from it that are too fixed rather than relative to material conditions. Let's not forget that the USSR suffered immense losses in order to beat the fascist German state. Meanwhile, the US, the center of rabid anti-communism, was in a strong position after the war and had not suffered much directly.

I know some believe the USSR stretched too thin and I don't think that's necessarily wrong, but consider the success of the US empire by contrast, which was also stretching itself out across the globe. It has taken much longer for the consequences of the US being that way to show up as decline and that's even with the US not giving a shit about its own citizens. One key difference here is probably the nature of exploitation, that some of what sustains the US (and the colonial world in general) is the parasitic relationship of exploitation they have with other nations to keep the shambling empire going. I don't know the details of the relationship the USSR had with every country, but based on what I understand, I don't think they would have been looking to exploit and get the impression they were giving without much return on it in some cases; which is commendable from a virtue standpoint, but not sustainable. If we compare to what China is doing, China does a third path, which seems to be mutual benefit / interdependence; both countries gain something without either exploiting the other and become more intertwined logistically in the process, which makes both stronger and makes it harder to isolate either.

Another difference is, circling back to the point about the state of things after WWII, the US had resources to wage the campaigns they did that the USSR simply did not have. Not only in relative health of things domestically, but also in the pre-existing colonial tendrils in the world. The USSR was trying to support socialism/communism, which had plenty of support in various countries, but if successful, would surely topple the colonial masters who have been ravaging the world for hundreds of years. So this was a threat to them, a threat to capitalism, a whole, drastic paradigm shift and one that the USSR had shown could happen pretty quickly. It's no wonder that the exploiting classes portray it as a monster under the bed. For them, it's the end of their existence as a class.

But I do not mean to imply fear is a significant factor here. Simply that they were up against a lot that had its roots in place for a long time. And they may have, in some cases, underestimated how deep and vicious those roots were. But whatever the mistakes made, they were already vulnerable from the immense losses they had suffered. I want to emphasize that point because I don't think the USSR and the US / western empire were evenly matched. I think the fact that the USSR accomplished as much as it did in spite of being under siege is a demonstration of just how effective socialist projects are. But they are still made of humans and still limited by logistics, and so no matter how well organized, there is only so much they can do. It's critical to understand the position you are in relative to others, in order to do what you can effectively with what you have. I'm sure in many ways, they did understand, but had they internalized it more so, they might not have stretched as much.

It's complicated though, getting involved vs. not. In retrospect, Mao was surely right to get involved in Korea. What if China had held back then? The whole of Korea might have become a puppet state. But then, the Cultural Revolution, some believe went too far. If nothing else, what I'm trying to drive at is that it is non-trivial to assess these things and get a clear answer.