Many of those who oppose providing military aid to Ukraine think of this aid primarily as an act of charity that we cannot afford. But almost no one knows about a significant event that occurred after the breakup of the former USSR.
Before the breakup of the USSR, they had the largest nuclear arsenal in the world (Russia still does). But remember, the Soviet Union was mostly Russia plus 14 other countries. When the break happened, Western world leaders at the time were concerned that nuclear weapons were spread around all these newly independent countries that may not be so stable, so a big move was made to try to consolidate those nuclear weapons in Russia.
We didn’t think Russia was all necessarily the “good guy”, but at least it was a large, strong, “stable” (relatively speaking) country.
So, in the mid-90s the Clinton administration went to Ukraine with a proposal that they give up their nukes… TO RUSSIA.
But Russia has been attempting to erase Ukraine as a separate country since at least 1804 (see Russia–Ukraine relations), sometimes with genocidal effect (look up Holodomor). And remember that during nearly all of Russia’s history it has been an aggressive, brutal, expansionist regime no less evil than Nazi Germany (in fact, if you didn’t know, in the first two years of WWII Russia and Germany were in a pact to be partners in seizing Poland. We only became “allies” with Russia after Hitler broke their agreement).
So when the West came to Ukraine asking them to hand over their nukes you can imagine their thinking! They KNEW, almost without a shadow of a doubt, that after Russia regrouped after their disintegration they would almost certainly resume their aggressive ways, and without nukes Ukraine would be a nice unarmed, defenseless target.
And remember, the first leaders of these newly independent republics (Ukraine, Belarus, Georgia, etc.) had previously held very high positions in the Soviet government and had access to the horrifying long-term plans (See Deceit, Dread, and Disbelief: The Story of How Ukraine Lost Its Nuclear Arsenal).
So when the West came to Ukraine demanding (more than “requesting”) that Ukraine give up it’s nuclear weapons, Ukraine wanted some assurances, and that’s the Budapest Memorandum.
Some dispute whether the memorandum is legally binding, and some note that the actual obligations of the west to provide “security” are not specific, but the general idea is CRYSTAL CLEAR: The world wanted Ukraine to give up its nukes, and those nukes were Ukraine’s only means of defense against a CERTAIN future Russian aggression.
And now MAGAs want to hang Ukraine out to dry.