Wouldn't you say the US is somewhat of an outlier w.r.t. government ability to undertake significant infrastructural projects?
Denmark, where I live now, has the luxury of commanding massive taxes from its citizens to finance its projects, all while putting a pittance of its share to its military. Denmark is also much, much, smaller than the US so the red tape that would be apparent at the size of the US is less apparent at the size of 6 million people.
We also overspend on grotesque, predatory contracting firms, just as the US does, to finance our public projects.
Well, so does the US - which is also able to do defict-spending much more easily due to the USD's role as a global reserve currency. But as you've pointed out, a huge part of it feeds the military-industrial complex - and that's a part (but not nearly the most important part) of how it struggles to expend on public infrastructure. Also, red tape is mostly not a per-capita thing; that kind of red tape is mostly in distributed execution rather than decision-making, legislation and such.
But point taken regarding Danish overspending on predatory contractors.