The US could halve medical spending per capita, use all the money saved to increase defense spending, and still have a better healthcare system with better health outcomes.
It's a false dichotomy to suggest that the US has to choose between more defense spending or better healthcare/education. Better healthcare costs a lot less in much of the developed world.
I did the maths, and if the US spent the same as South Korea does on healthcare, America would save roughly 2.4 trillion dollars. In other words, the US could double its military spending, and still have more than enough to offer every American better healthcare and better education.