Nuclear power for starters. Look at the rate at which USSR was building nuclear power plants. Many of them are still operational (i.e. Zaporozhina in Ukraine). Energy usage under capitalism is also inefficient, as is the infrastructure upkeep - one of the worries about nuclear are various incidents, but those can be (and are) prevented by timely upkeep and maintenance.
After that, it is entirely possible for fusion to start being viable.
And this is on top of the still-visible effects from the 90s economic collapse and the increasing pollution by various sources. Several people I know personally had noted their sinuses and throats “suddenly” felt much clearer after leaving the city and visiting places outside - i.e. mountains in Kazakhstan
Also, looking back at the title, I have to disagree. “They” have learned a very valuable lesson from this war - anything goes. The ghost of USSR is finally at rest, there is no-one left to challenge the Hegemon. No lie is too blatant, no atrocity too great. They can do anything and get away with it.
archive.ph and archive.is