Think of it from Zelenskyy's POV:
His country HAD a security guarantee in exchange for giving up nukes. That guarantee was not honored by the Russians. First in Crimea, then in a full fledged invasion by the Russians. He's only asking for the tools to defend his country from obliteration. He's not asking for bodies. He's fighting for his country's sovereignty. Now he's being asked to give up a chunk of his bank account (rare earth minerals etc) but he wants ironclad guarantees because he knows how well the Russians honored the last guarantee.
Remember he sees daily his country is having its hospitals and schools and residential units and power grid routinely blown up by rocket attacks. He also knows a Russian takeover means certain death to a big chunk of Ukrainians, through arrests and unfortunate falls from windows.
For less than 5% of its DoD budget the USA was able to knock out a third of the Russian army. One of the best investments it has ever made. Plus it's learning from the Ukrainians new tactics.
The framing of this in that white house "discussion" disturbs me. It's like there is a sense this war with Ukraine v Russia was 2 blokes going the biff in a bar fight. But this was an invasion, more like a mob of blokes attacking someone on their front lawn. And the bloke forced into a fight on his lawn is the problem? There is no war if the Russians leave Ukraine. So somehow it's Zelenskyy who is fighting for his country's freedom with the Russian army inside his country attacking his army AND civilians is somehow the one prolonging this? If he stops fighting he and his country are doomed.
That's why he's willing to resign and/or give up the minerals but he wants an ironclad guarantee. He remembers the last guarantee.
Every country in that region has a history with the Russians. None of it is good.
Now a side effect of Trump walking away is all of the US allies in Asia are shitting their pants as they realize US security guarantees mean nothing. Or will be amended to look like a protection racket. This will lead to nuclear proliferation as it seems the only way to stop invading powers is to have nukes. The south Koreans have been advocating for nukes but the Biden administration said we got your back, no need for you to have your own nukes. Now that a USA security guarantee is worth shit, what do you do?
Either open the door for china, let them bully and pillage your resources, or Japan, south Korea, Australia etc will want and try to obtain their own nukes. Likely followed by every other country on earth.
And more nukes = more chance one gets free and finds it's way into some terrorist group.