Die Ukraine hat Trump endlich aufgegeben

What choice did they have? Trump abandoned Ukraine the moment he set foot in the white house.

The only reason it took so long is because Ukraine needed to source assistance elsewhere. 
Intelligence data? France. 
IFVs? Sweden. 
Ammo? The EU.
Financial assistance? The EU.
Long range missiles? Domestic.
Air defense systems and missiles? The EU and domestic.

When Trump said Ukraine needed to do what the US said because they didn’t have the cards, Ukraine systematically began stripping away the cards America had on it. 

Now Trump can tweet, and whine, and piss all over himself, but he can no longer pressure Ukraine, because America no longer has any leverage to do so

What, other than the fear of an American response, is stopping Putin from doing the very bad thing, though?

Trump destroying Usa, lost every ally.

Of course. They probably had longer ago but held on to some vestige of hope that playing nice with him can still gain support.

Well, trump is a dementia putin bitch, so all anyone can hope for is that America finally gets its shit together