Trump did win. America lost. Some people just aren't bright enough to figure that out yet. Of course, that has nothing to do with a line of reasoning that might be seven times as deadly as another line of reasoning. Try to stay on topic.
I would think they could look at the flight path on radar and determine what kind of missile it was, where it was launched from, how fast it flew, etc.
About all Trump can do is cut the funding and tell Western Europe they can take up the slack if they want (which they wont). As far as any peace plan Russia won't be giving that Donbass area back so that is off the table. There are a few little areas Russia holds they probably dont care about long term but it's not a lot. Basically Western Ukraine has nothing to bargain with and Russia holds all the cards and Trump doesn't change that. Ukraine should have been wiser and not let the western crooks use them for a proxy war and money laundering operation. I guess Zelensky won't care much long term as he is set up to live a real good life after all of this with some of that money.