I mean, if we're going to play shocked, pearl-clutching humanitarian, this conversation will be even less fruitful.
We judge the worth of a cause every day from the homeless panhandlers you drive by to the countries we send missiles to. Don't be intentionally obtuse.
The Nigerians aren't offering us the opportunity to decimate the military capacity and reputation of a geopolitical adversary.
Part A: That's MMT, which I certainly don't make arguments for. The spending increases matter, but they matter as part of an overall economic problem. They do not matter in regards to Ukraine, because the funding for Ukraine does not represent specific type of spending that, if halted, would solve our budgetary problems.
A weak analogy: If you have hypertension because you only eat bacon and chocolate burritos three times a day, you have a heart condition that could kill you when you exert yourself. But when the neighbor's smoking-hot ex-wife is putting the last of her things into the U-Haul, and she offers you VIP tickets to the suck parade for helping her get the tailgate closed, one might argue that your heart-condition is going to be materially worsened by by accepting her offer of oral nirvana. But it wasn't MILF blowjobs that put your heart at risk, and this opportunity is about to drive away forever. So you do the math and take the risk, because at the end of the day it's your addiction to deep-fried butter that put your heart in danger.
Part B: There is no "healthy for the country" solution; we are well past that. The disease is now a cancer, and the treatments are all going to be a whole lot more painful than life would have been if we had just put sunscreen (balanced budgets) on in the first place. But there are treatments, and they will still work in the future, though they will be more painful the longer we wait. A lot is going to depend on the attempted bifurcation of the world currency system by China and Russia. They might be able to accelerate the collapse of fiat to the point we see some solutions in the next decade as opposed to the second half of the century.
With the worldwide decline in birthrates and the suicidal refusal to produce cheap energy, the grow-our-way-out-of-it solution that the entirety of the planet has been relying on seems completely unrealistic. So that leaves the really shitty solutions.