It is the classic battle of Guns versus Butter that all Great Powers in decline have faced, Butter usually wins out because it has more constituents. You just have to take a look at Europe and what they spend on defense. The US has provided the security umbrella to allow them to feed their welfare state. We won't have that luxury as our power declines.
“classic battle of Guns versus Butter that all Great Powers in decline have faced”
A stark factor here is that our huge military strength makes us desirable as an investment safe haven: thus reducing our borrowing costs- the money we borrow for the butter. There are many other economic benefits of a dominant military we will lose, which will also raise the cost of ‘butter’.
I’m sure this spiral has been discussed of previous great powers’ decline.
Cutting guns is also cutting butter in a case of debtedness such as ours.