This is an interesting piece about two different ways of seeing the end of the (first) Cold War and the dissolution of the USSR. The first view, shared by Reaganites and socialists alike, is that what happened was that the Gorbachev leadership of the USSR came to see sense and the Soviet Union came to (re-)join the international family of nations: it was a joint victory of both sides over an 'Evil Empire'. The second view is that there was a war which the Soviets lost: there was only victor, and that was the West.
The point of this is not to decide which is the 'right' model of what happened. Rather, the point is that these two models give very different views on what should have happened since. For example, why, on the first view, should the Soviet Union ever have been disbanded? Once its leadership became democratic, what objection could there be to the country continuing in its old borders (my caveat: give or take a Baltic state or 3)?
The other point the author makes is that the facts change perceptions. It just becomes harder, in a world of (for example) an expanding NATO, to believe the Reaganite view of history: "In the same way that Germany was shocked to have learned when it went to Paris in 1919, that it was there not to sign an armistice but a capitulation on very costly terms, thus the Russia under Putin began to reassess how the Cold War really ended." That view naturally tends to produce a narrative of defeat and revanchism.