Our posture toward Russia (nee USSR) and other "CIS" states is quite similar to that taken by the UK and France toward Wiemar Germany after 1919. They then, like we now, assumed that the end of hostilities (in our case, the "end of the Cold War") had brought on an unprecedented era of peace and an end to total war. The mistakes they made were to allow many small known infractions to the Treaty of Versailles, to put in place a weak and ineffective inspection process, and, this is key, ignorance of the trick of the use of operations outside of Germany to develop both new weapons and to manufacture weapons not subject to the treaty.
Today, Russia has many treaty infractions to account for, we put very little investment into inspection, and, the relationship by Russia with the PRC and other anti-Western states allows Russia to coordinate de facto rearmament not subject to any current treaty. Our failure understand fully the mistakes made by the UK 1919 - 1939, and, to view the current world situation from a more deterministic, purely geopolitical perspective, is, I believe, a grave error.