The question arises as to what more the Europeans and the Americans could be doing on Ukraine’s behalf. Much of the blue-check answer to that end is unrealistic: a no-fly zone is indistinguishable from a full-on tactical-air campaign versus the Russians; and of course immediate Ukrainian admission to NATO or the European Union automatically draws the whole of those alliances into the war as well. The people warning against those outcomes are right, and the people warning that we need to think hard about the escalatory pathway to nuclear war are also right. To the extent that this, to them, militates against further action — which to date has mostly been extraordinary fiscal sanctions plus arms delivery plus stale intelligence — they have defensible premises undergirding their analysis.
Nevertheless there is as much analytic skew on their end as there is on the part of unmoored maximalists among the neocons and neolibs. If the latter warn of the consequences attendant to American / European action, then the former artificially reduce the plausible scope of that action, and thereby ending up making more war more likely. The ur-mistake in this vein was probably when they got their policy preference a few months back in the form of an explicit American promise to not defend Ukraine: you may be able to draw a direct line from that to the war now. (Probably, may: we must qualify all this, as the clarifying archives won’t be open for generations.) The lessons and mechanisms of deterrence used to be a commonplace among Americans of ordinary civic awareness, but after a generation of great-power peace, we have forgotten.
Drawing from the history of U.S.-Russian confrontation across the past seventy years or so — including within the past five years — we can produce several insights on options for that confrontation now. They follow here in no particular order.