you need to put forth a reasonable effort to fully arm your own country.
Not addressing this as you defending Trump here but just making a general observation/comment....
The above is what makes Trump's position on Ukraine even more idiotic. Ukraine was told in part by us to NOT fully arm, and we'd protect them. We've softly prevented/asked them not to join NATO. A true "we are all looking for the guy that did this" meme moment if there ever was one.
On principle, I can somewhat see wanting an ROI (or more of an ROI) for our military investment. Trump is a child/simpleton/idiot though so he sees everything through the spectrum of dollar in dollar out. That's not how the world works and that's now reality works...anywhere....not even just in politics.
Even removing Ukraine from the equation the US reaps massive economic prosperity through our military investment. Our military investment helps stabilize countries, regions, and organizations to the point where we gain trade and open economic opportunities. We have seen and continue to see how even the invasion of Ukraine has destabilized the US/world economy. How destabilized would the world economy be without organizations like NATO over the last 70 years?
The US is something like 25% of the entire world's GDP. The large price we pay for military help/stability I think has a pretty nice ROI right now. Could the argument be made the ROI could or would be better so we can massage some things around the edges? Sure.....but I think that's a world away from the wholesale abandonment of Ukraine or going to the extent of siding with their invader.