In order for "American to win" as you say. It seem important that what happened in Crimea 7 years ago, and what happened in Feb 2022 is not repeated.

Putin just opening killed an opponent. and this is such a regular occurrence in Russia as to be joked about. Threat of force or actual force is the only meaningful language here. Of course diplomacy can perhaps find tradeoffs acceptable to all so it should be considered.

But clearly a mistake of 7 years ago was allowing a military takeover to be complete w/o serious loss. It made the present conflict thinkable, and potentially "winnable" by Russia. This was a failure of foreign policy.

How do you propose we avoid making that mistake now? this was a failure of politics, but now I see few options except to make this be a dramatic failure for Russia.... and it has to LOOK like a dramatic failure to its people too. Else it is spun to be a partial win. One that needs to be repeated in order to complete that win.

So that is my question: How can we negotiate and end which make subsequent aggression unthinkable?

You might answer: we just don't do anything provocative. But Ukraine is naturally leaning towards the EU, and will only accelerate for economic reasons. Even if they promised never to join NATO, but became ever closer to the EU (including militarily) it is still a dramatic loss of power for Russia. So how is that acceptable? and not being acceptable, how to we disincentivize another Crimea.