“By the time of the first ceasefire in September 2015, Russia had withdrawn all line units from Donetsk and Luhansk, leaving behind advisors, contractors, and some special forces.”
So you admit that Russia had combat troops in eastern Ukraine, and some remained after 2015 (advisors, contractors, and special forces; just what we had in Vietnam prior to 1965... and those troops participated in combat operations). At least you are acknowledging that, because there are pro-Russia FReepers who deny Russia had ANY combat troops in eastern Ukraine between 2014 and the 2022 invasion.
“In fact, all light engagements and heavy fighting in these areas from 2016 to 2021 were between the Ukraine army and the DPR and LPR militias.”
And Russian assets (such as “contractors” like the Wagner Group such as Wagner Group) were involved in some of those operations (though the Wagner Group during this period was also involved in operations in Syria and Africa; basically, wherever Putin needed them).
“As for the heavy equipment, neither the Ukrainians nor the DPR and LPR removed their heavy equipment from the agreed-upon 30 km demilitarized zone.”
That’s true. But neither did Russia.