Years of fiscal malfeasance and so-called "mandatory" spending are really the biggest part of the problem. Even eliminating all discretionary spending (which includes defense) wouldn't be enough to balance the budget this year. Your statement "THAT is the amount that funding this war diminishes" doesn't flow logically. What other funding has Ukraine aid "diminished?" If the government decides to spend $2 billion on an aid package, it doesn't suck away $2 billion from other things. That's not how the federal budget works. Maybe your statement was just hastily phrased?
Again, Ukraine aid has literally jacksquat to do with the ridiculous situation on our southern border and illegal immigration. Illegal immigration exists largely because of the byzantine and limited system designed by an incompetent government that limits ways to come here legally, even for immigrants who'd be a boon for the economy, and/or who fill jobs that many Americans don't want to do (and the latter is separate issue in and of itself). Both parties are more interested in grandstanding about the issue than doing anything meaningful to address the problem. We need better security and enforcement, but at the same time need to recognize that the system itself caused the present situation. Realistic, rational reform is needed and achievable. Immigration is good overall because it helps stabilize the population, making the demographic outlook better than it would be, which is important for the solvency of programs like SS and Medicare, which already look precarious.
Anyway, I feel like we're veering way off from the thread topic (and it's all your fault!).