Z can not win. Those who call for continued war should 1. pay for it, and 2. sign up BECAUSE, Z needs bodies for the slaughter pen.
Trump isn't sending U.S. troops, nor is the U.S. taxpayer going to fund the war any longer.
The Europeans can not go it alone, they would immerse themselves in a quagmire, the butchering and slaughter would continue, at an astronomical financial cost, not to mention the body bags returning to London, Paris, etc....European citizens aren't going to put up with that.
Russia does not, and will not, accept U.S. nukes on it's border, as U.S. would not accept Russian nukes in Canada, or Mexico, or....Cuba.
Ukraine will not be a NATO country, as that would instigate, upon attack, a world war. Who's going to sign up for that? Ukraine must remain neutral.
To sign an agreement with the U.S. would have been a fantastic move for Z. It would have put the Americans squarely in Ukraine.
My guess, Z, after a serious lashing behind the scenes, either steps down, or comes groveling back to Trump, as there is no other way.
My opinion.